I've searched and have some success trouble shooting but still not happy. So I have a 72 Cutlass S. Tail lights come on with headlights on and brakes. Except upper passenger. It comes on dim and doesn't brighten. The drivers front doesn't light at all. What I've done:
New bulbs 1157
Cleaned sockets and soldiered in new connectors in sockets bc of corrosion
Replaced both flasher cannisters


The headlight switch is finicky and you have to pull just right for tail lights and dash lights to work. And I don't have signals. The stock clicks in position but nothing happens.


Tips for more troubleshooting? I have a turn signal switch but don't want to dig into the column before I have to.
Replace the headlight switch?


Thanks for the help.


Matt

 

You might have a bad headlight switch, you shouldn't have to wiggle it to get park lights or headlights. Sounds like the internal contacts are worn out.

If you have no signal lights? Check the flashers. (not sure if that's what you call cannisters?) There are 2 of them:
1 located on the fuse box
1 located on a pigtail by the steering column.

If either of those are missing or burnt out you will not have flashers. Do your emergency flashers work? If they do, that flasher is good. Try putting it in the other holder and see if it works the turn signals. Use a process of elimination or you'll never figure this out.

As far as the RS upper light? Check your electrical connector in the trunk, and also make sure the ground at that light is good. IIRC the ground will be the bolts holding the light bucket to the bumper - check there for corrosion. The dimming of that light is classical symptom of bad ground. One other thing you can do is a continuity test on the socket and wiring harness to see if there's a problem in the wiring harness.

I hate electrical gremlins. They have the best hiding spots.

 

I agree with Allan, you might get a new switch to start with. Dim lights can be poor grounds, or loose connections. Also double check the splice joint where the wire branches out to the other light.

 

Use a multimeter to see what voltages you are getting at the various connections, you shouldn't see more than a half volt drop between voltage across the battery terminals and the wire furthest away from it. Check you have a good ground at the light units by checking resistance between them and a clean metal surface on the body or chassis. It should be a few thousandths of an Ohm.
Like Allan and (other) Eric say, you need a new light switch, but I doubt that will be the end of your problems. Be patient and methodical and you should fix your problems, and possibly uncover some potential problems and deal with them before they cause trouble at an inconvenient time or place.

Roger.

 

Thanks guys. I will change the switch out this winter hopefully. I replaced both flashers, one in the dash wiring and one in the fuse box. What next to trouble shoot the flashers. I know this question is asked all the time but electrical gremlins are tricky suckers!

Matt

 

Also check that the spring contacts to the tail light bulbs work freely. The springs can get junked up and then not tightly return the contact after you insert the bulb. Mine were like they were "glued in" and were loose, causing intermittent or dim condition.

 

I have a couple of questions, so here goes

1. Do the emergency flashers and signal lights work if the lights are not on? When you try to use the turn signal stalk, do you get a solid green indication with no flashing, or no indication at all on the dash?
2. Do all the lights work in the A) park position, B) headlight position? Is there a difference in the tail-light dimming in either of those positions?
3. When you replaced the sockets in the rear light pod, did you remove the light pod or bumper from the car to gain access? The ground on both of those light pods is through the bolts that hold them. They need to be clean and free of grease/rust. Any chance the bolts on the upper pod are slightly loose?
4. Do the brake lights all work properly with lights off and lights on?

I don't think the problem you have is related to the signal stalk on the column.