Tail Light Diagnosis

[KiDD3]

I'm trying to figure out my taillight/brake light problem, assuming I can describe it correctly:

Tails on: both sides work
Brakes on: Left side on, Right side off
Right Turn and Brakes on: works correctly
Left Turn and Brakes on: works correctly

Seems that if a wire was crossed, everything would still function, just burn on the wrong filament. I've spent days trying to figure out why I had a brake light sometimes and other times I didn't, only to notice they worked with the left turn/brake light combo...

Ideas?

[nightmare]

Are you sure your getting a proper ground? I think that the housing is grounded to the bed, which in turn is grounded to the frame. Also, just to make sure, the light isn't burnt out, right?

[68gmsee]

Grounding issues can cause you headaches. I had the same type problems on my GMC. Seems like the sypmtoms would change everytime I'd try something different.

One thing I did to help is polish the contacts of all my rear bulbs. I used a pencil eraser and some real fine sand paper.

Read my post on this problem. And what I did to resolve.

http://67-72chevytrucks.com/vboard/s...ight=grounding

[Longhorn Man]

not a ground problem.

Try this, with someone watching the tail lights, hit the brake pedal, and hold it down, and lightly wiggle the turn signal lever. lightly forwatd and back, up and down, but not enough to turn on the flasher.

If that right brake light lights up, it's time for a new turn signal.

You know the bulb is good, the tiurn signal lights up.
You know the wire is good from the turn signal, the turn signal lights up.
you know the ground is good, the turn signal lights up
you know the brake light switch is working, the left brake comes on.
The turn signal switch is pretty much the only cause.

[MikeN]

I had a similar problem and it was a bad ground...

[Longhorn Man]

you had a problem where the turn signal would light up, but no brake light, unless the OTHER turn signal was on, and then that brake light that was previously out... would work....
and it was a ground?

[KiDD3]

Originally Posted by Longhorn Man

not a ground problem.

Try this, with someone watching the tail lights, hit the brake pedal, and hold it down, and lightly wiggle the turn signal lever. lightly forwatd and back, up and down, but not enough to turn on the flasher.

If that right brake light lights up, it's time for a new turn signal.

You know the bulb is good, the tiurn signal lights up.
You know the wire is good from the turn signal, the turn signal lights up.
you know the ground is good, the turn signal lights up
you know the brake light switch is working, the left brake comes on.
The turn signal switch is pretty much the only cause.

Kind of my thoughts but will try both the ground and the wiggle trick...

[Infanti]

I had the same problem.What Longhorn Man describes is exactly what my problem was.Sometimes brake light worked sometimes it did not.Wiggled turn signal lever and noticed lights would work.Turn signal contacts just needed a little bending in my case.

[KiDD3]

Definitely is the switch as I wiggled that and the light works. I switched the steering column a couple of weeks ago, possibly didn't get something back together quite right. Anyone have an exploded diagram/pic of how all of this goes together?