bxd76

Hello.

Newish to these forums, I'm now seriously working through this car and expect to be here often.

The left turn signal works normally.

The right turn signal flashes the correct set of lights in front BUT flashes both sides of lights in rear(as if hazards were on), albeit faintly, not at normal brightness.

Where should I start?

Thank you !
Brian

m371961

I would first check the ground on the right tail light. Each light has it's own ground. If the right side does not ground, current travels through the bulb to the tail light circuit, and finds the ground on the other lamp.

joe_padavano

X2. This is the problem.

bxd76

Thank you for the tips, gentlemen.

I got underneath the back bumper. All of the wiring looked PRISTINE, like it just came off the assembly line. This car was always a garage queen, in an attached garage. It never saw rain, let alone snow.

Nevertheless, I undid the snaps that cover the wiring loom, and carefully pulled the wires out of the loom. They look great, no abrasion or pinched spots. I checked those wires all the way from each bulb to where the wiring disappears into the body, which it does on both driver and passenger sides, before heading forward somewhere.

So I'm still stumped.

Previously the right turn signal flashed very slowly.

Today it was just steady on.

None of the bulbs are burnt out. Not only is it illuminating both sides of rear turn signals, it is also illuminating the REVERSE lights (very dimly) on both sides. Perhaps that is a hint?

If I put the car in reverse, the reverse lights illuminate at normal brightness.

m371961

Have you removed the right side bulb? The bulb base grounds to its' socket. A dirty socket, the socket not grounding to the housing will cause this.

joe_padavano

The reverse light circuit is COMPLETELY separate from the turn/stop and tail light circuits. The only thing they have in common is the battery and chassis ground. This tells me that there is a pinched wire bundle somewhere the the dash harness, the body harness that runs under the carpet, or the trunk harness.

m371961

Does reverse light the taillights?

bxd76

Again, thank you for the tips guys. I've been away a little while because my uncle was hospitalized and has been very weak since getting home. All my extra energy and time has gone into caring for him.

Back to looking at the car......

Patrick - If I put it in reverse, the rest of the taillights do not come on. Only the reverse lights illuminate, and they are as bright as they should be.

Also, are you sure the sockets serve as ground? The lamp assemblies appear to be plastic, and the sockets themselves appear to be an off-white plastic. There are at least two wires going to every bulb. 2 wires to reverse, and 3 wires to the other taillights. Isn't one of those the ground?

Where in the trunk would I find a wiring harness? The wires in the loom disappear into a grommet in the body on BOTH the driver and passenger side, just ahead of the rear bumper, and seem to run straight forward. It doesn't seem like any of the taillight wiring actually runs through the interior of the trunk.

Perhaps it's an issue within the bulb sockets. If I pull a bulb out, the factory original grease is still in there. It's pretty hard at this point. Cleaning that out and putting fresh dielectric grease is probably worth my time.
HOWEVER.... if the reverse and taillights are separate circuits, I don't see how that explains what's going on.

So I'm thinking it may be a pinched wire under the dash. Does anyone know exactly where the harness is under the dash?

THANK YOU!
Brian

bxd76

PROGRESS.

I got back to messing around with the wiring in the rear, and playing with the bulbs by swapping them side to side. I noticed that at times, the signals would then work correctly.

Through process of eliminating, I found TWO things were happening that were making this such a head scratcher to figure out.

One, there was a poor ground, but not at the chassis. There is a black ground wire that spans the width of the rear that is connected in the middle with a spade and lug, this wire is inside the conduit. That spade and lug was connected, but surface corrosion had begun to make it a poor connection.

At the same time, I was also battling a contact problem within a bulb base. The old bulb grease was very hard, crayon like. It was keeping the bulb from seating and making contact correctly. I removed all of the old bulb grease and filled the base with fresh dielectric.

Things are good now.

Thanks for everyone's ideas, they were the motivation I needed to keep pushing forward.