Hitman's Pontiac Trans Am Forum
Trans Am Information => Trans Am Tech => Electrical => Topic started by: NY78TA on July 27, 2006, 01:16:57 PM
-
Have had my 78 TA for a couple of weeks.
Back up lights won't come on.
Changed back up light fuse and 1156 bulbs (which looked old). Suggestions? I'm thinking next step is to check the shifer. its an auto.
All other lights are fine.-Alan
-
check your connections going into the light socket...
-
You can also check the switch with an ohm meter. You can also unplug the connector and check for 12 volt coming through. That switch controls your neutral start also...well it's park and neutral.
To check the switch, disconnect the back up light connector and hook up an ohm meter to the connector blades. As you move the shift lever to reverse, you should be able to see the circuit close...and then open for all other selections.
I assume you can only start the car in neutral and park.
-
Thanks for the tips guys...
So far this is the only real problem I found. :roll:
Other than this, the car just needs a lot of tightning up.
The water temp guage is out and the previous owner hooked up a working temp gauge under the dash with some wires left hanging. Is there a reproduction GM guage for the dash?---Alan
-
It's probably not the temp gauge. Nine times out of ten it's a bad circuit. You need to unhook the sender wire at the temp gauge (it's located in the head between cyclinder 1 and 3. With the sender wire off, turn on the ignition and check the gauge...it should read below 100 degrees. Now ground the wire with a jumper and check the gauge with the ignition on, the gauge should read way past 260 degrees. It this doesn't happen, I bet you've got a break in the plastic circuit between the oil gauge and the temp gauge (the oil gauge works, doesn't it?). These gauges share the 12 volt circuit. Voltage passes through the oil gauge then to the temp gauge.
Check the circuit with an ohm meter and also use a mangifying glass to visually check for breaks. Get rid of the alien temp gauge!
Now that I think about it, you've probably got the sender wire hooked up to the foreign gauge so the test above wouldn't work. You need to trace the green wire from the sender and undo what has been done to get the car back to how it's suppose to be.
Good luck, it's not really that hard.
-
You also might want to check the rods and linkage from your tranny to the steering column. My buddy did not have reverse lights because he was missing these rods that control that. When you turn the collar on your steering column, do the lights come on?
-
Brett,
That's why I was asking about the neutral start. The back up lights and neutral start work off the same switch (which works off that rod). But the more I think about it, that rod also works the key out mechanism. So if his problem is isolated only to back up lights, the problem is most likely at the bulb socket like eroc022 said.
I would think if the switch is bad, he would also have problems starting in neutral or park (the switches can get dirty and cause the circuit to close). And if he was missing the rods from the tranny, he would be complaining about getting his key out (unless the lever from the column was moved to the highest position and left there).
So Brett, did your friend have a manual transmission? Otherwise he should have had problems starting the car as well as no lights in reverse.
-
It pretty common for guys to wire up the arm on the column under the hood so the car will start with the shifter is in any position if they lose/damage some linkage. That would be the first thing I'd check. If the collar on the column inside the car will rotate clockwise with the key switched to the first position and it not effect the shifter position then i'd say you need to round up some linkage. Post back and let us know.
Russ is a guru on the wiring for sure. So if it's not mechanical... Post back cuz he's da man!
-
Hey Guys, I appreciate all the feedback on this back up light problem.
I've had the car two weeks and very jazzed over it.
The car starts well in park or neutral. Key works fine. Steering locks perfect.The shifter doesnt light up when i turn on accessories w headlight on. All other lights work incuding dome.I dont remember if my old 78 TA PRNDL lit up either?
The added temp gauge and get this it has a wiper delay gizmo added too. I'm dying to remove it, but fear the wipers will go out ?
Will try again when weather cools down a bit. It was in the 90's today in New York! Alan
(http://i3.photobucket.com/albums/y73/Alanny/interior.jpg)
-
No, his car started and worked just fine. It was an automatic, had no problems with the key or antthing with it.
There is a light by the PRNDSL so that just might be a bulb that is out.
-
Checked car this morning , car starts in neutral, steering column clicks in sync with shifter.-Alan
-
No, his car started and worked just fine. It was an automatic, had no problems with the key or antthing with it.
Brett, if your friend didn't have the rod, then the column lever in the engine compartment must have been put in the highest position. This would enable the car to start (but in any gear) and the key to come out. All that stuff is mechanical and works off that rod.
It makes me crazy how people take things off, cut wires, and generally make a mess of these cars.
-
Brett, if your friend didn't have the rod, then the column lever in the engine compartment must have been put in the highest position. This would enable the car to start (but in any gear) and the key to come out. All that stuff is mechanical and works off that rod.
Uh oh! I have a 4-speed and the guy I bought it from said "It has to be in reverse to take out the keys". I did that for a while, but then accidentally took the keys out in neutral, but with the ignition not turned back all the way.
Is that a problem?
-
It could mean you're missing the reverse lock out rod that Brett was referring to. The rod attaches to a lever on the bottom of the steering column....in the engine compartment. The rod comes up from underneath the car past the area between the head and the firewall on the drivers side. A quick way to tell if you have the rod is to put your hand on the lower part of the column (just under the ignition lock), then move the shift lever from reverse to neutral....you should feel the column rotate. If it doesn't, you don't have the rod. If it does, you've got some other problem such as your ignition lock is worn out. Or the mechanism inside the column is fouled up.
Also, if your backup lights work properly i.e. they only go on when you're in reverse, you've got the rod.
But as Brett's friend found out, many times these rods are taken off. Good luck finding one for a 4 speed. I saw one on ebay several weeks ago but it wasn't complete.
The other part very hard to find for a four speed is the clutch start switch. It only allows the car to start when the clutch pedal is depressed. I only have one spare and I look for these constantly.
-
yep, no rod. i learned that the hard way. backing out of a buddy's driveway with no lights on the street, and no back-up lights. i just tapped the brake every once in a while to see where the heck i was going.
oh well.
-
ebay seller "goodwoodcedar" had one for sale that no one bid on. You might look him up and see if he still has it.
But check the engine compartment for the rod. There's a lever attached to the bottom of the column just as the intermediate shaft connects. The rod attaches to that lever.
It's possible the switch could be unplugged or your backup lights could be burned out.
The rods come up on ebay every so often...and I believe the rods for the auto are different than the rods for the manual transmission.
I have a tilt column on my workbench. The key will pull when the lock is in any position. The key is worn down to the nub. The lock works ok, and everything within the column seems ok....so I think when the key is worn way down, it will pull out without being in the lock position.
-
I have a set on Ebay right now for an automatic.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=200010287726&ih=010&sspagename=STRK%3AMESE%3AIT