Topic: electrical gurus, need your help

[Nexus]

Just keep at one step at Time. Get one problem Solved and move on to the next and you'll find you won't be as overwhelmed or frustrated with the issues. I had similar issues with an old bike. Took me a couple months to workout all the gremlins and now it runs great.

Your doing a good job so don't give up now

Charlie

[78ta]

I'm sorry to hear you're still having trouble. I can see how it would be even more frustrating given the fact that you want it done for her as opposed to just doing it for yourself. But still, sometimes, you just have to walk away from a project for a few days.

One thing I would suggest to help reduce your frustration level would be to work one problem at a time. It can get overwelming trying to solve three problems at once.

I noticed in the pic that the hood appeared to be open. If it's been like that a long time, I wonder if the latch and or hinges just need to be lubed.

A quick (I think) check for the light issue would be to swap in another dimmer switch. Or simply disconnect it and use some jumper wires to verify that the dimmer switch is operating correctly. The light blue wire going to the dimmer is the 12v supply wire coming from the head light switch. Just take a jumper wire and connect the lt blue wire to the tan wire and see if the 2 outer low beam lights come on. Then connect the lt blue wire to the lt green wire and see if the high beam (all 4) lights come on. This is with the head light switch pulled out of coarse. Also, make sure your battery is charged up well. There was a post recently where someone thought their power windows stopped working and it turned out that their battery was just very low. As we found out the other night, these halogen bulbs apparently require a lot of current.

If the radiatore has been sitting a long time, it could have a lot of sediment. You might try putting some radiator flush in it. Or just disconnect the upper and lower hoses on the engine side and put the garden hose to it and see what your flow looks like. I've heard of some reverse flushing theirs by putting the water hose into the lower hose and running it through backward.

Oh, I just remembered that there was a post just the other day in which an engine was over heating and they showed pics of the head gaskets. I'm no expert but it looked obvious to me that the gaskets were blocking 95% of the water passages. The cutouts for the water passages in the gasket, supposedly the correct one, were no where near being in the correct location or large enough. I'm sure you don't want to pull your heads off but it's something to keep in mind after you've tried the simple fixes like flushing the rad, changing or removing the thermostat etc.

[78cali]

I'll do that today and see if the switch is the problem. Battery is strong, not only is it brand new but I'm also using a brand new 100 amp alternator.

You're right, tackle the problems one at a time. I just got too excited because of the dedication. I drove her out of the garage and it sent tears to my eyes because it reminded me of her so much. It's like the car's alive and ........I don't know, hard to explain.

[78ta]

You're right, tackle the problems one at a time. I just got too excited because of the dedication. I drove her out of the garage and it sent tears to my eyes because it reminded me of her so much. It's like the car's alive and ........I don't know, hard to explain.

It wouldn't be as much fun if it was easy.  It will be all that much more gratifying when you get there. And you will. All of us here will do our best to make sure of that.

Happy thoughts,
Randy

[skisix38off]

I just got my 78TA and am having some some similar issues with the headlights and horn and lighter and wipers.  I read through theis thread and got a list of things I can check( I can use a voltmeter)...

So, let me ramble some things that come to mind:

I have a grnd wire going from the front wire harness to the radiator core support and it's tight but I didn't check the wire where it comes out of the harness.  I didn't measure any volts on any of the wires to the headlights- I think this means that they don't have any volts on them but, I think you are saying that it could be a ground somewhere...  I have a grnd cable going from the block to the subframe but no grnd from tranny to subframe....

The I have drive lights, gage lights, but no hazards...

the headlights switch has 12V coming into it but I don't know which terminal I should be looking for to send power to the headlights.  The floor switch has power and it toggles as the swtich is depressed....

On the Wipers- I measured 12v on the motor and then when the selector was set to low my meter could settle on a votage on a green/black wire( I think that was the color) indicating to me that the power was being pulsed perhaps?  Does that sound like a bad wiper motor or a frozen wiper motor?

Thanks!

[78ta]

skisix38off,

I didn't measure any volts on any of the wires to the headlights-

You won't have any voltage on the wires unless the head light switch is pulled out.

I have a grnd cable going from the block to the subframe but no grnd from tranny to subframe....

just to clarify, the subframe is the frame section that the suspension and motor mount to. The braided ground wire should go from the rear edge of the passenger side head to the firewall(the chassis). There should also be a braided ground going from the transmission(auto) or bell housing(manual) to the subframe on the pass side.

The I have drive lights, gage lights, but no hazards...

This could just be the flasher module.

If you have 12v at the dimmer switch, then you have 12v coming from the headlight switch. The wire coming out of the switch to supply the head lights is brown or tan.

[skisix38off]

Thanks Randy,

I am clear on the sub-frame...  The gnd on my car goes from the pass. side head bolt to a bolt on the subframe just below the head.  That's the only one I saw there but, I will check again a little more closely and resprt back.  I can make a gnd to go from the auto trans. to connect to the same point on the sub-frame id that would help?

I also looked more closely at the fuse box into the firewall and that is very loose.  I tried to tighten it without removing either the hood or the brake booster and was only able to get in there with a 1/4" driver plus extensions and tightened the screw until I thought I was in danger of breaking the socket or the externsions I was using and the fuse box was still loose on the firewall.  I will go at it again this morning when I can start to make noise, any tips on how to get at this or what can be removed to make this easier?

At the same time I ohm'd out the headlights and found the bottom of the three prongs was going to grnd ( ~1-3ohms to chassis and battery).  I turned on the lights and then tried the trick about taking a second wire from the headlight grnd prong to the battery and still no lights....

skisix38off,

I didn't measure any volts on any of the wires to the headlights-

You won't have any voltage on the wires unless the head light switch is pulled out.

I have a grnd cable going from the block to the subframe but no grnd from tranny to subframe....

just to clarify, the subframe is the frame section that the suspension and motor mount to. The braided ground wire should go from the rear edge of the passenger side head to the firewall(the chassis). There should also be a braided ground going from the transmission(auto) or bell housing(manual) to the subframe on the pass side.

The I have drive lights, gage lights, but no hazards...

This could just be the flasher module.

If you have 12v at the dimmer switch, then you have 12v coming from the headlight switch. The wire coming out of the switch to supply the head lights is brown or tan.

[78ta]

I am clear on the sub-frame...  The gnd on my car goes from the pass. side head bolt to a bolt on the subframe just below the head.  That's the only one I saw there but, I will check again a little more closely and resprt back.  I can make a gnd to go from the auto trans. to connect to the same point on the sub-frame id that would help?

Well, the ground from the head bolt _should_ go to the chassis(body sheetmetal). Not from the head bolt to the sub frame. I'm not sure if we're having a problem with terminology here. You need a ground going from the engine to the sheet metal and from the trans to the sub frame. The ground from the tranny to the sub frame is near the oil filter if I recall correctly.

I think the bolt you are tightening behind the brake booster is the bolt for the bulkhead connector that connects the front wire harness to the main body wire harness. Not the fuse box. The bulkhead connector bolt is hard to reach with out removing the brake booster. I think it only takes 4 nuts to remove the brake booster but be very carefull to keep it supported if you're not going to disconnect the brake lines. I think you could lean it forward enough to make room to reach the bolt better. I'm pretty sure the fuse box screws straight to the sheet metal from inside the passenger compartment.

If you know you have a good ground(by ohming it out) at the head light prong and the still did not come on when you touched a wire from the pos batt cable to the other prongs on the bulb, that bulb is bad OR your battery is dead. If you suspect the battery, and don't have a spare battery sitting around, pull another car up and use the battery from that car to do the test. Just remember to run a ground from your car to the new battery.

At the same time I ohm'd out the headlights and found the bottom of the three prongs was going to grnd ( ~1-3ohms to chassis and battery).  I turned on the lights and then tried the trick about taking a second wire from the headlight grnd prong to the battery and still no lights....

This bothers me a little. I can't get to my car but I have the service manual with me on vacation for reading material. Not sure what says about me. Anyway, according to the wiring schematic, one of the vertical prongs is the black ground wire. Not the bottom horizontal prong. The wire attached to the bottom(horizontal prong) is labled "BLK/GRN LT". I think that's black with a light green stripe. It's the 12v supply for the four high beam bulbs. If you have a good ground from the core support to the chassis, and touch a 12v wire to this prong all four high beam lights should come on together. By the way, you don't have to have the head light switch pulled to make this test. The ground is alwaysthere and you are supplying the 12v directly from the battery.

You said before that you measured 12v at the head light dimmer switch, the tan wire coming from the dimmer switch is the 12v wire going to the low beams. The light green wire is the 12v wire going to the driver side high beam bulb. This wire splits and goes to all four high beam bulbs. If you have 12v at the dimmer with the head light switch pulled out, you should have 12v at the bulbs. If you don't, you have an open wire between the head light switch and the light bulbs. The only connection between the two is the bulk head connector.  
Again, make sure you're battery is charged.

[skisix38off]

Yeah!!!!   I now have headlights, flashers, wipers, horn and e brake the works!!!!!!!  I can pass an inspection not to mention not stress about being caught in the rain or past dark!!!!!

I think now that this was several problems and some bad timing.... 

The headlights- after dinking around with the fuse box bolt in the engine bay and getting no joy from that I thought I was in for some very serious work and called in a friend.  While waiting for him I noticed a brn wire on the fuse box was split and I repaired that, then I noted that on the lower left side of the fuse box under the dash there was a screw that was loose so I ran it back in to tighten and then wondering what just happened I connected the battery and ....I have lights.  I still don't have brights but I the dimmer switch has to be the issue. 

Wipers- just probably haven't run for years, a good wabik with a dead blow and they are running again. 

Horn- missing the ground....  That one took a while to figure and test to prove....

I still think I have some issues to resolve with the bulkhead bolt that you referred to, and I have to add some more grnds- we didn't have a terminology problem Randy, we are understanding each other.

So, I have enough to get on the road now and can take my time in making everything last for another 31 years....

Thanks so much to everyone for the nice tips and suggestions!!!

[78cali]

Hey Randy,
Sorry for the silence, I was rushed to the hospital and suffered a mild stroke. I still have some questions for you and I hope you don't mind if I email you instead.

[78ta]

Hey Rene',

Yeah, well... you needed something else to deal with. Right?   WTF.

I hope it was very mild and you're ok now. That's nothing to mess with.

Email me anytime. w70442@hotmail.com

[78ta]

skisix38off,

Glad you're up and running.

Yeah, if the car sat for a while or the car is new to you, that would explain several things seemingly happening at once.

I am clear on the sub-frame...  The gnd on my car goes from the pass. side head bolt to a bolt on the subframe just below the head.  That's the only one I saw there but, I will check again a little more closely and resprt back. I can make a gnd to go from the auto trans. to connect to the same point on the sub-frame id that would help?

Obviously, you're getting some kind of ground because things are working.

However, I know you said we understood each other about the difference between the subframe and chassis but your wording above doesn't give me a warm and fuzzy feeling that we do. If so, I aplogize for beating a dead horse but just to be sure, there are two main grounds........
One ground wire from the passenger side head to the firewall. This one seems to missing on your car.
And one ground wire from the bell housing(if manual transmission) to the sub frame OR from a mounting bolt on the automatic transmission to the sub frame.

My concern is that if your car has a ground wire going from the passenger side head to the sub frame and you add a ground wire going from the transmission to the sub frame as you mentioned, you're not including the chassis sheet metal anywhere in that equation. The electrical system relies on the chassis(body sheet metal) itself having a good ground path to the engine block along with the sub frame being grounded to the engine block through the transmission via a ground wire.

[skisix38off]

Thanks Randy,

the car runs now and could pass inspection so that I can get it registered in my name and get my plates on it and be all legal and such- that's been the top priority....  The stereo, an aftermarket one, stopped working on Sunday- just when I was starting to relax a little and think about cleaning/detailing the engine bay and looking at the mechanicals....  So, I took apart the radiio bay and then saw this and that wasn't right so.... the dash is torn down agai, although this time I think the stereo itself is the culprit and none of the wiring.  But, in the process I'll mount the tac/speedo cluster to the dash( no screws were in that cluster) and the light bulb from the climate controls had fallen out and I can poke around the cig lighter while all that's going on.  Plus the black bezels that go around the gages fall out very easily so I'm going to try and get them to stick in the dash bezel a little better.
I know....  Welcome to classic car ownership!!!  I'm having fun discovering the car, please don't mistake my list of things that need reapir as complaining...

Grounds- All I have found is the grnd from the block to the sub frame.  Period.  There's a grnd from the head light harness to the radiator support too.  So, I need to grnd the firewall to the engine block and then add a grnd from the tranny to subframe....  Can I pick a mounting screw from something already mounted to the firewall?  I'm pretty sure that's a yes but wanted to ask.... 

skisix38off,

Glad you're up and running.

Yeah, if the car sat for a while or the car is new to you, that would explain several things seemingly happening at once.

I am clear on the sub-frame...  The gnd on my car goes from the pass. side head bolt to a bolt on the subframe just below the head.  That's the only one I saw there but, I will check again a little more closely and resprt back. I can make a gnd to go from the auto trans. to connect to the same point on the sub-frame id that would help?

Obviously, you're getting some kind of ground because things are working.

However, I know you said we understood each other about the difference between the subframe and chassis but your wording above doesn't give me a warm and fuzzy feeling that we do. If so, I aplogize for beating a dead horse but just to be sure, there are two main grounds........
One ground wire from the passenger side head to the firewall. This one seems to missing on your car.
And one ground wire from the bell housing(if manual transmission) to the sub frame OR from a mounting bolt on the automatic transmission to the sub frame.

My concern is that if your car has a ground wire going from the passenger side head to the sub frame and you add a ground wire going from the transmission to the sub frame as you mentioned, you're not including the chassis sheet metal anywhere in that equation. The electrical system relies on the chassis(body sheet metal) itself having a good ground path to the engine block along with the sub frame being grounded to the engine block through the transmission via a ground wire.

[78ta]

Welcome to classic car ownership!!!  I'm having fun discovering the car, please don't mistake my list of things that need reapir as complaining...

Grounds- All I have found is the grnd from the block to the sub frame.  Period.  There's a grnd from the head light harness to the radiator support too.  So, I need to grnd the firewall to the engine block and then add a grnd from the tranny to subframe....  Can I pick a mounting screw from something already mounted to the firewall?  I'm pretty sure that's a yes but wanted to ask....

You're welcome.

Yep, that's the "fun" of owning a classic.  

Yes, you could pick a hole something else is already screwed to on the firewall. The firewall is pretty thin metal so be sure to sand the paint away right at the hole so that you do get metal on metal contact for a good ground. Same goes for the head though it's not as critical because that bolt will have several threads that will come into contact with the metal of the threads inside the head. They generally suggest using one of those star washers with the sharp points all around it. Those dig into the paint to scratch down to bare metal. I'll try and remember to look at mine to see if there's a specific hole on the firewall it's grounded at.

[skisix38off]

Now, on to other issues with the same car...

The gas gage is reading off- at empty( I wish I didn't find this out the hard way) the gage reads 1/4 and at full the gage goes well beyond full.  I thinkt he span of the gage is correct but it's start point is off- How do I adjust that?

I broke the 12V tab on the cig. lighter and I don't think I can solder it back on well enough to have it last- can I just buy a new one or do I need to go to a junk yard or trans am bone yard to get another one and hope it's in better shape?

As always, thank in advance for your help.