Hitman's Pontiac Trans Am Forum
Trans Am Information => Trans Am Tech => Electrical => Topic started by: rkellerjr on January 20, 2007, 04:03:19 PM
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As everyone knows, TAC went poopoo and so this thread is currently lost. Today I got out and tore into my wiring under the hood. Here's what I've done and then I'll tell you the symptons I'm still having...
* Replaced battery
* Replaced battery cabes
* Replaced battery terminals
* Replaced alternator (internal regulator)
* Had replacement alternator tested - tested good
* Replaced two prong plug that goes into alternator
* Replaced wire that goes from the alternator to the starter
* Replaced wire from the firewall to the alternator (spliced into existing wire at a good point then ran to alternator)
* Replaced wire from the firewall to the starter (spliced into existing wire at a good point then ran to starter)
* Replaced wire from the firewall to the brown wire (spliced into existing wire at a good point then ran to brown plug wire)
* Grounded engine to frame (didn't make a difference so I removed the ground)
OK, there was some great information in this previous thread that I lost and I no longer have for reference so I need ya'll's input again. Using the dash voltmeter gauge she stays in the yellow. I ran down to Advance and had it tested and it's coming back as if the alternator is not charging like it should. Like a bad regulator in the alternator but when the alternator is tested, it tests fine. Now, prior to my playing with the wires and removing tons of splices in the wiring, some were even hanging by two tiny threads, the car would and has always, started fine. The voltage would read in the yellow. After the car warms up to about 180 the voltage would swing up to 13.5. When this happens the lights get bright, the power windows work well, etc. So when the gauge reads yellow (11) it really is in the yellow as far as charging the car. Now, even after warm up, she just stays in the yellow. It's charging just enough to keep the battery from dieing as she continues to start fine even after running her for a while.
Another strange thing I found was that the brown wire and the red wire that come out of the plug were actually spliced together at some point. I unspliced them and ran them separately as I thought they should be. Whoever did actually cut out a sqaure in the rubber of the red wire and rapped the brown wire, bare, to the red wire and taped it. When I saw that I thought, hey, that's more than likely my problem but, alas, I'm still fighting this thing.
So, what I need is someone to help me out in how I need to test this thing with a volt meter or any other ideas that might help.
It's pretty maddening after spending 4 hours on this thing running wire and it not being fixed.
Thanks for the replies guys, I'm also going to post this over at TAC in case folks aren't looking here.
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Ok, I have a couple of stupid questions.
I'm assuming the wires you're talking about connecting to the starter are the ones at the large lug (where the batt. cable connects) right?
Where on the alt is the red wire connecting? How large is this wire?
Have you hooked a test volt meter to the batt when the engine is running both cold and warm? If so, what were the readings?
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Ok, I have a couple of stupid questions.
I'm assuming the wires you're talking about connecting to the starter are the ones at the large lug (where the batt. cable connects) right?
Where on the alt is the red wire connecting? How large is this wire?
Have you hooked a test volt meter to the batt when the engine is running both cold and warm? If so, what were the readings?
Question1: yes but actually, I replaced all three wires coming from the starter. I wanted to be thorough.
Question2: There are two red wires from the alternator, one from the plug and one from the 3/8" nut. The nut one is 10 guage and the plug looks to be 14 guage and I spliced that into 10 guage.
Question3: I took it down to Advance and they put it on a tester. I did not write down the numbers and I don't remember the numbers he said. He did indicate that all numbers were way low. His assessment, alternator or could be wiring :shock:
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Ok, that all sounds good. They said it could be the alt, but you said that was tested and was good right?
Where does the ground from the alt go? To the frame or the block?
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Ok, that all sounds good. They said it could be the alt, but you said that was tested and was good right?
Where does the ground from the alt go? To the frame or the block?
Yes, that was tested and it tested good...
:shock: Ground for the Alt? There isn't one. Only three wires coming from the Alt, two reds and the brown (from the plug) which I believe runs to the meter in the dash.
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Oops. I means ground from the batt. :oops: Meaning the neg. batt cable.
Where does it go/attach?
Actually the brown wire is the "trigger" wire which energizes the alt. field to start the charging. Without it the field won't energize until the engine is revved off idle.
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Battery negative is attached to the steering pump bracket.
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Battery negative is attached to the steering pump bracket.
Try grounding the block to the same point using similar size wire to the red one (at least).
The guy who taught me about automotive electrical taught me a rule about grounds. He said there should be good grounds connecting the battery neg., the engine block, and the frame/body.
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Battery negative is attached to the steering pump bracket.
Try grounding the block to the same point using similar size wire to the red one (at least).
This didn't make sense to me. You want me to ground the battery to the body, not the block, then ground the block to the body in the same place? I have an extra battery cable to do this so yes, same gauge will be used.
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Oh hell, never mind. I didn't read what you put right. (Got too much arguing and yelling going on behind me. :x
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Oh hell, never mind. I didn't read what you put right. (Got too much arguing and yelling going on behind me. :x
hehehe, careful bud, your talking to someone who doesn't know what he's doing so I have complete trust in you :shock:
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Ok, is the bolt you have it grounded to going into the block? Is it a good ground? (Meaning free of paint or other materials that could hinder it?) Maybe run a tap into the hole to clean up the threads.
Since you have gone through all the trouble that you have to make sure all the pos. wires are good it makes me think the trouble is on the ground side.
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Oh hell, never mind. I didn't read what you put right. (Got too much arguing and yelling going on behind me. :x
hehehe, careful bud, your talking to someone who doesn't know what he's doing so I have complete trust in you :shock:
Sorry, I was really hoping both of the girls would be going out to Aimee's ex's this weekend. Only the 12 y/o did. The 8y/o is really trying my patience. Seems that even though she doesn't have to share Mom's attention with her sister, it's not good enough. I think this will be another good thing to come of the new shop. It will give me some place to go and get away when I need to. Even if I don't have anything to work on.
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Hmm.... well, I can move the ground to the bolt on the thermostat which I know would be a good ground. I'll try that Larry. I'll also put the other cable there and ground it to the body. I'll test that tomorrow. Appreciate you "chatting" with me on this tonight.
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Hmm.... well, I can move the ground to the bolt on the thermostat which I know would be a good ground. I'll try that Larry. I'll also put the other cable there and ground it to the body. I'll test that tomorrow. Appreciate you "chatting" with me on this tonight.
NP 8)
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By the way, your new avatar is somewhat disturbing :shock:
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By the way, your new avatar is somewhat disturbing :shock:
(http://i20.photobucket.com/albums/b230/SirLDragon/Just4Rich.jpg)
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My car was grounded to the pump too. However, I moved it to the correct ground point which is directly to the head just to the left of the number one spark plug.....that's for a 1978 Pontiac 400.
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Rich -- do you have an electrical schematic of the engine? If not, I've got one in photobucket I can post. It really helps to "see" where these things go, especially if your wiring has been hacked.
And Larry is right -- the ground connections make the "return" path for the current coming out of the battery and off the alternator, so they have to be as good (preferrably better) than the +12 VDC connections going out.
Let me know if you want me to post it.
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Some times the main electrical harness where it plugs into the back of the fuse box gets coroded where the copper terminals meet each other. you said you tied on to the brown and red wires that go to the starter solenoid and alternator but the problem would be between your splice and the ignition switch where the alternator field wire signal comes from.. So to test my theory we must run jumper wire from the alt wire spade on the ignition swith on top of the steering column to the alt field turn on the voltage regulator terminal on the alternator wich should turn on the voltage regulator and cause field excitation and stator generated current flow to the battery which should bring the battery voltage to 13.8 volts as indicated by the dash volt meter or voltagemultimeter checking directly across the battery. However; If I am wrong the car will burst into flames and Explode so use extream caution...
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Rich I have both of my batteries negative cables running to the cylinder heads. I ground off a bare spot free of paint and surface rust at a bolt hole then bolted them to the heads. Seems to work out pretty good. Another thing to try might be running a good wire from the alt. output post to the positive battery terminal. I looked in my photobucket and I don't have a good pic of the charging system or wiring. If you need it let me know and I'll brave the cold to take a few pics. :D
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Rich, first lets talk about your problem. You say the alternator will charge at 13.5 volts after the engine warms up? What about when you first start the car what does it charge?
My car does a similiar thing. It wont actually start charging until you bring it above idle and then it will "kick in" and start charging. From then on its ok. I personally dont think there is a problem with this.
I am going to post a picture of my engine. If you look closely you can see where my ground wire (black wire) connects to the engine head. It is towards the front of the head, forward of the temp. sending unit, on one of the head bolts. This is where you need to hook the ground coming from the battery. Now, there is also a ground located on the back of the engine, near the distributor, that goes from the back of the engine block to the firewall. This grounds the engine to the body. Make sure both of these grounds are clean and are making a good connection.
(http://img440.imageshack.us/img440/4269/picture0141bw.jpg)
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Rich, first lets talk about your problem. You say the alternator will charge at 13.5 volts after the engine warms up? What about when you first start the car what does it charge?
My car does a similiar thing. It wont actually start charging until you bring it above idle and then it will "kick in" and start charging. From then on its ok. I personally dont think there is a problem with this.
This is what AmTrak and I were also referring to about the brown wire from the ignition switch energizing or exciting the field coil. If that doesn't happen raising the idle slightly does it.
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Here's my 2 cents worth...
1) It is critical that the engine AND body have a path to
the negative side of the battery. Quite literally the
metal of the engine and body IS part of the circuit.
Think about it, one battery lead (+) to the distributor?
The spark plugs couldn't spark unless they were grounded
into the block.
Often we tell folks that their dash lights/gauges need a
good ground to work. The engine needs the ground straps to
the body.
It's not important electrically "where" the battery cable
bolts to the engine.
2) Two things about alternators...
A) They don't work unless a 12v source feeds the field. Less
than 12 less than advertised output. (I'm simplifying a lot)
B) Auto Parts places don't test re man units quite as well
as you'd think. Intermittent or marginal units may escape
their "testing"
3) Engine harness, is this thing hacked up? could there be any
shorts to ground? Bad connections?
Summary
Maybe you have a weak "new" alternator, maybe the strain of starting
pulls down the battery enough to effect the voltage applied to the
alternator field. The diminished output (from low field voltage)
eventually bumps the battery up high enough to properly stimulate
the field and it's output comes up to specs.
Maybe you have a short/drain to ground pulling down the battery
voltage down until the alternator output can finally overcome it's
load. Have you tested for parasite loads?
Joe
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Wow, looks like I've got a lot more to look into.
I was taking my dash apart and noticed wires coming in through the firewall behind the kick plate. That is not good. Closer inspection reveals that at least one of these wires may be the main power coming from the alternator into the cab. If so, I need to double check, then it looks like they may have bypassed the engine harness layout. If this is the case I'll need to rethink this whole situation and by an engine harness and re-wire ... again. I may also by a dash wiring harness to make sure I have a good fuse box in the car. This is daunting to me to say the least but, it can't be helped if this is the issue. Or at least if this is hacked in this way, I won't feel safe unless I re-wire the these two components of the wiring system.
Thanks guys for the input, I now have a source if information to come back to. I'll keep ya posted as to my progress. I'm starting to believe it's the exciter wire that may be the problem and not the ground but, I need to look into how much the wiring "might" be hacked as it comes into the car. As I said previously, the exciter wire was actually tied into the main power wire coming from the alternator under the hood.
Anyway, wish me luck!
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Thanks guys for the input, I now have a source if information to come back to.
That's assuming Rick and Milly don't succeed in crashing the forum like they did TAC. :lol:
Larry--->Who just can't let it go.
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I did not have anything to do with Rick crashing TAC. That's Ricks baby. :twisted:
I can tease him for now. He is going to watch the Patriots beat the Colts in the AFC title game tonight. :wink: :P
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And you can get ahead of him in posts while he's watching the Colts!
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Heck Rich, I can make up some time on him AND watch both of todays football games. :D
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Oops. I means ground from the batt. :oops: Meaning the neg. batt cable.
Where does it go/attach?
Actually the brown wire is the "trigger" wire which energizes the alt. field to start the charging. Without it the field won't energize until the engine is revved off idle.
Larry, My first 76 TA did something very similiar. When you cranked the car the volt gauge would only show about 11 volts no matter how long it sat there and ran. Even if you drove it the gauge stayed around 11 volts. But if you revved the motor to 2500 RPM's or more the volt gauge would jump immediately over to about 14 volts and stay there until you turned the car off and then same thing over everytime.
Are you saying that's normal?
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He is going to watch the Patriots beat the Colts in the AFC title game tonight. :wink: :P
You got it half right -- Colts win 38-34, but you know that by now.
I burned up half a lifetime worth of adrenaline during that game -- feel like I ran every play with the players... :shock:
Rick ---> who has never seen 60,000 people so excited...
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The negative cable should attatch to the front frame and then you should run a ground strap from the block to the frame. If your wiring is that I messed up then I would buy a Painless kit. The Painless kit is very easy to install and it will also upgrade your fuse block. I am an electrician so I always find wiring easy. Good luck.
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I thought I'd give everyone a little laugh. :) I drove the TA to work today as I have a meeting and will be late getting out of work. This allows my wife to have a car to get home on time. We car pool most days. I use the TA maybe once every week to two weeks for work. Well, I get here and guess what? :? The battery is dead!! :shock: :shock:
So much for my wiring job last weekend!! :evil: Back to the drawing board with ya'll's suggested ways of finding the problem.
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Heres something else to check. With the battery fully charged, unhook the negative cable. Make sure everything is off including the lights, radio, ignition switch etc.
Then slowly touch the negative cable back to battery and look for a spark. (you may have to do this in the dark) If you get any kind of spark that means you have a dead short somewhere. Maybe in the wiring harness or something.
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I think I asked you back on TAC but have you checked the fusible links,Rich?
BTW, I know diddly about electricity, but I had similar problem with my T/A years ago and a link was the issue :roll:
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Hey just wanted to follow up on your alt wiring. the flat plug on the alt has two wires coming out of it the brown wire goes to the ignition switch and the white wire does tie back in with the heavy wire that is bolted to the alt.. This is called the sense wire it is used by the voltage regulator to controll the output voltage from the alternator....... This should answer all your alternator problems good luck and may the force be with you......
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Then slowly touch the negative cable back to battery and look for a spark. (you may have to do this in the dark) If you get any kind of spark that means you have a dead short somewhere. Maybe in the wiring harness or something.
What... ? <grin>
Ok, where on earth did you hear that?
Seriously, what's needed is a way to measure current flow.
The static charge on the body or even the capacitor in the ignition system could store enough to give you a cute little zip.
Joe
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If you want to check current draw then put a clamp on style amp probe on the positive cable. If you are drawing current then pull your fuses one at a time untill you losse the draw and that will at least point you in the right direction.
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Then slowly touch the negative cable back to battery and look for a spark. (you may have to do this in the dark) If you get any kind of spark that means you have a dead short somewhere. Maybe in the wiring harness or something.
What... ? <grin>
Ok, where on earth did you hear that?
Seriously, what's needed is a way to measure current flow.
The static charge on the body or even the capacitor in the ignition system could store enough to give you a cute little zip.
Joe
Its shade tree stuff that your not going to find in any book but it works.
I have been a mechanic for over 25 years now, so I really dont know where I first heard about it.
The capacitor in the distributor is for radio noise suppression and nothing else. Unless its shorted out, your not going to get any kind of spark.
Im not even going to touch the static charge thing. :roll:
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Eagle 1,
In re-reading the thread and my own input, I want to
make sure you don't think I was giving you a hard
time. If so, I apologize.
As I read your suggestion I couldn't initially see
where it would identify a problem (circuit). As I
re-read it, I now see what you where saying...
Not any specific circuit - just that one somewhere
could be a short.
So Yes, I would agree an unknown short to ground would
yield a spark - A fairly noticeable one too probably.
I had never ever heard that trick, and I too have a
few years of wrenching - just not as a full time job
though. In High School, I took 4 years of Auto Mechanics,
graduating in 1975.
Then in 1980, I got a B.S. in Electrical Engineering and
that too never became a full time day job.(Long Story)
When I picture electrical troubleshooting I tend to
get a tad overly analytical.
Connecting the negative battery cable closes any and
all active circuits on the car. Even if you've turned
off switched circuits there are still several that are
always hot like say the clock.
As soon as you close any circuit by manually making
the contact you can have a slight spark. It would
stand to reason that the greater the flow through a
specific circuit the larger the potential spark.
If you metered the connection you would have way more
info as to how much juice is getting loose. That was
where I was going.
As far as the capacitor, yes it's for noise suppression,
but any capacitor can in fact hold a charge, granted
not for very long usually. Any wire or metal that cuts
a magnetic field will induce/conduct some electron flow.
Since a car is a collection a large metal sheets
insulated by 4 rubber tires any field or fields nearby
can and do induce a slight charge. Then closing the
battery cable closes the isolated loop and the charges
equalize (a spark).
Ok, so that's the short story and maybe I'm a ding-ding,
but that's what I was thinking - not being critical
of your tried and true wisdom.
Joe R
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Then in 1980, I got a B.S. in Electrical Engineering and
that too never became a full time day job.(Long Story)
Hey -- me too! Mine was a full-time job, then another full-time job, and finally it turned into MORE than a full-time job so that's when I took a line from the old song and said "take this job and shove it!".
The donkey might be dumb, but if you keep loading stuff onto it sooner or later it will lay down... :evil: 8) :lol:
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What I was always told is kind of a combination of the two. Disconnect your battery terminal (I don't think it really matters which one), and put an amp meter in series between the battery and the cable end. If you have any draw at all, pull out fuses until it goes away. Kind of like the clamp-on meter idea, but you don't need a clamp-on meter.
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Yeah, that's a draw test. Anything over .01 amps (I think that's the correct number) is too much. The clock and maybe radio memory will pull that much. The neg/ batt cable test is the same idea. It's just the way they don't tell you about in school. :lol: The slight draw from those same things probably won't cause enough of a draw to create a noticable spark. If you can light your cigarette off of it you're in trouble. :lol:
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No problem Joe.
Rich mentioned back on the first page that he didnt know much about this so I was just giving him an easy way to check it with out going into much detail.
Just to let you know, I asked a couple of buddies from my shop and they agreed the method I described is the easiest way to check for a dead short; and your right you will get a fairly noticeable spark.
I agree the clock is the only circuit in the car that will be drawing a small amount of current and I had already thought about that, but my clock works and I dont get a spark when I hook up my negative.
Its good to have people on here like you who specialize in specific fields.
Mean while back to Rich's problem. If your wiring harness it all chopped up I would recommend you consider replacing it. It is only going to lead to problems in the long run. I have seen cars with shorted wiring catch fire.
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Larry regarding the acceptible draw, on newer cars and trucks 0.5 amps is considered ok because of all the electronic jumk they add on to cars today. On a basic older car (no cumputers) the .01 you posted MIGHT be ok. It's really hard to day depending on the options that the car has or was added onto. :?
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Mean while back to Rich's problem. If your wiring harness it all chopped up I would recommend you consider replacing it. It is only going to lead to problems in the long run. I have seen cars with shorted wiring catch fire.
Ultimately that is my plan but I don't have the money right now to do that. I'm going to pull the wiring harness ... uh ... block/box from the firewall :? and then make sure the wires are ran correctly. Then check the interior and make sure things are fine there. I will be only concentraing on the charging system mostly as everything else is fine. I am way out of my league here but, it must be done. I've got several wiring diagrams (thanks Rick!!!) and my service manuals so .... I shouldn't have any problems ... I hope.
I'll be pushing the car away from the house though :shock: just in case, and I do have plenty of insurance :lol:
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Are you 100% sure of the alternator? I had a similiar issue with my car, and had my original alternator rebuilt. It now is over 14 volts at idle. He was pretty sure the voltage regulator was acting up. Just another though - maybe you might want to take your alternator to a specialty shop (instead of Autozone, Advance, etc), just to make sure if you haven't.
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Well, this is the 2nd alternator to act EXACTLY the same way so I think it's the wiring and not the alternator. Anyhoo, my plan is to pull the engine harness block from the firewall Sat. morning and then start tracing and re-wiring the charging the system. Then put the block back on and see what happens. HopefullyI'll have a running and charging car.
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Should the engine harness block plug into the cabin block? How do the two connect?
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It's a big plug that plugs into a receptacle on the firewall. It has a bolt in it that keeps it in place. Have you looked at the Hoghead page? http://www.firebirdtransamparts.com/techinfo/harness/harness.htm It shows some pretty good pics.
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Well, no joy. I'm going to get me one of those painless wiring kits and re-wire it. If that doesn work, I'm gonna shoot it.
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(http://members.cox.net/r.p.keller/icons/Red75TA.gif)(http://members.cox.net/r.keller.jr/smiles/frocket.gif)
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Find someone who is into wiring to help you taking out the harness and puting a painless harness would hurt the value of the car and be a Nightmare to install. You have at the most two bad connections somewhere one hour at a garage that restores old cars and this would be fixed...I would help you myself but you live on the other side of the US
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After thinking through my options I think I will probably take the car down to a reputable local establishment that specializes in car electricals. That is my least expensive and least time consuming route.
Thanks everyone for all your posts and help. As usual you've been a wealth of knowledge and support. I'll let you kow how it goes.
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Well, the car is being dropped off tomorrow to an auto electrician to figure what's wrong with it. I'm tired of messing and the alternatives are too expensive and may not fix the problem. I should know where I sit tomorrow as they indicate they can get it in and diagnosed. I'll keep ya posted.
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It's been a while since you posted rich.. any word on what was the ultimate problem? There's so many postings and the story has climaxed.. It's like clue.. I'm curious to find out who did it, in which room, with which weapon. hehe.
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It was Rick...in the Lobby...with a connecting rod ;D
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hehehe, the problem ended up being that I had one wire not connected right on the alternator. I don't remember which one since it's been so long however, I still do not think it's 100% correct as there isn't a fused wire, which I think there should be according to the wiring diagram. I will probably get an engine wiring harness later this year and replace all the wires.
It's charging great now.
And actually Jeff is WAS Rick.... in the engine bay... with a connecting rod ;)