While driving to a cruise in tonight in my 72 Cutlass Supreme, the person behind me told me my right brake lights weren't working. I've got tail lights, but the turn signal doesn't work either. I suspect the bulbs are bad, but I dunno how to get them out to check/change them. Do I go up from underneath? I tried removing the assembly, but once I took the screws out, it wouldn't budge. I have a Fisher body manual coming, but if I could get a head start, I'd like to try.

Thanks,
Dave

 

You need to remove the lens. There are four Philips head screws, one at each corner of the lens.

 

I took the screws out but I couldn't get the lens to budge. Should it just come right out?

 

Sometimes it sticks to the gasket. Use a dental hook or something to grab behind the lens through the screw hole and pull outward.

 

I'll give that a try...thanks

 

I had the same issue with my 72 when I bought it. Bulbs were fine. The contacts are spring loaded. They pushed down, but were very sluggish coming back up to make proper contact with the bulb contacts. The wires going in to the back of the sockets have to more through in and out when the contacts are depressed. The sealing shroud around the wires (for weather proofing I suppose) was dried and too tight. I had to relieve that pressure to allow the wires to move freely to get them to work. As I recall, to get to those housings for the sockets, the bumper needs to come off. Now, 12 years late I think I need to rep[eat that for my right side.

Anyone have an easier fix?

 

I remove the bulb, squirt some WD-40 into the socket base, then reach up behind the bumper and push the wires back and forth until they loosen up and move freely.

 

^^^^THIS. If it still has it's original gaskets the lenses will be almost glued to them. Gently massage all corners of the lens and use a flat pry to go between the lens and the bumper to help apply slight pressure. They will release but it might take a bit of time and patience. Use 1157 or 1157A bulbs for replacement. If the bulbs in there are only 1 filament they are 1156 and won't work with brake or signal lights.

 

For clarification, the 1157 bulb has clear glass and is appropriate for the tail lights, whereas the 1157A has a amber glass and is appropriate for the front lights.

 

WD40...that's a great idea!😀. I'll give that a try. I bought a couple sockets tonight just in case...and while I'm at it I May As Well (there's that word again "MAW") do the other side too.

Will let everyone know how it goes.

 

I got the lenses out with no trouble using a scribe with a 90 degree hook, and the bulbs are dual filament clear 1157s.

Question though...are the upper and lower lenses interchangeable?

 

If my tail lights work could it still be an issue with the contacts in the socket?

 

Yes, tail lights and brake/signal lights are 2 different circuits or elements in the bulbs.

 

So there's a good chance that the WD40 trick may work?

 

No, they are different sizes.

The contacts can be pushed up to clean them or you can use a fine wire brush like the kind used to clean copper pipes

 

Tried WD40 tonight and even let it soak. Was able to move the wires but still no brake lights or turn signals. What I don't understand is if it were the spring contacts thats causing the problem, then why do my tailignts work? I get that they are separate crcuits, but the spring contacts move together, so unless the contacts are moving independently, I shouldn't have tail lights, right? Oh, and I noticed the left side blinks slightly faster than the right...dunno if that is part of the problem, but I thought I'd throw it out there.

If I do replace the sockets, is there any way around removing the bumper?

Thanks,
Dave

 

Have you checked to see if you have voltage on the contact in question?

 

That was gonna be my next step. To check for voltage with a test light I would put the probe of the test light on the contact then ground the test light on the socket, correct? And if I have to change the socket, which two wires would I cut and splice?

​​​

 

Ok...so I unplugged the main harness in the trunk and hooked up another socket with a bulb. Still no turn signal on the right rear. All other lights and turn signals work including the right front. Both indicator lights work on the dash as does the flasher. The left rear hazards work as well, but nothing on the right. So I'm thinking the problem lies farther up the circuit. I replaced the turn signal switch a couple months ago and everything worked then. At this point I'm thinking it may still be a problem with the switch, so I was gonna check the circuit at the switch. To do that, do I probe that contact with my test light and run to ground?

I'm hoping it's not the switch, so if anyone has some more suggestions, please let me know.

Thanks,
Dave

 

Quick question - If you put on the hazard lights do you get all 4 corners blinking?

 

Nope..both fronts work and left rear but no hazards on the right rear..why do you ask kind sir?

BTW I'll be back at it tomorrow morning bright and early so any info that could give me some direction would be greatly appreciated!
Otherwise I'm gonna take the back seat out and check the wires that run underneath to the rear body connector...not a fun thing to be doing in hot weather with 75%+ humidity😥 but I gotta find the issue, so whatever it takes...

Dave

 

Each side of the rear bumper has it's own pigtail connectors to the lamps. Have you cleaned the contacts that go from the lamps to the connectors? The other thing that comes to mind is the main connection in the trunk. It's clipped to the left side of the trunk along a pinchweld and you should be able to trace back to it really easily. That connector can cause a problem with the brake lights if the contacts there are dirty or not pushed in well. Try cleaning it with contact cleaner and then re-insert it. I had this problem on a friends CS and it turned out that wiggling the connector got the brake lights working that were out on his car.

 

Select the right turn signal. Check for blinking voltage with a test light on the green wire that goes into the light socket. If there is no voltage there then you need to need to test at the steering column green wire. The connector at the steering column needs to be together with the key on. Just poke the test light into the back of whichever side is easier to get to. If there is no voltage in either place then its the directional switch. If there is voltage in the back then the bulb is not making contact to the socket. If no voltage to the back but there is voltage at the column, then its a broken wire or bad connection at a connector.

 

Eric, there shouldn't be any problem with the green wire from the front. It feeds both sides of the tail lights through a common feed. The left side is working but the right side isn't. That's why I think the connection at the right side pigtail is the problem. BTW there are 2 green wires to each side of the tail lights, not just a single. It's got to be something in that connector or a continuity/ground problem with the lights. Dave said it worked fine a few months ago, and if the front signal is working, it's not likely the switch.

 

Problem solved...apparently when I was installing my gauges I must have disconnected the side of the turn signal switch that feeds the right rear just enough to break the connection. When I saw this and plugged it back up I thought "no way it could be this simple.". But sure enough, that was it😀. I'm happy to say all lights are working as they should.

Thanks to all who lent their insight during my time of confusion....now onto the rear driver side quarter window, but that's another day...too hot in SE VA to be playing outside today.

Allan, pls check my post in the body and paint section. I have a question about the rear quarter window.

Dave

 

Just going by the schematic that I found. The green wire at the tail lights is for stop and turn signa, brown is used for tail lights on both sidesl. The turn signal switch has 4 contacts 1 for each corner.

Glad you found it.