Funky back wiring

[TC_cruiser]

Howdy everyone,

 

I just recently purchased a '89 Auto TC- it's a pleasure to drive and very well maintained for it's age, but I am running into some problems with wiring. The second day I drove it, I got pulled over for having a third brake light out. I took it to my friends house and we got the third brake light housing out and rewired/rebulbed with fresh 921s and... Nothing. We're getting a current to the bulbs when the brake is pushed, but nothing is lighting up. We had them briefly turn on with the old (broken wires) but after splicing they wont work at all.

 

Does anyone have experience with this same problem, and what additional diagnostic information should I provide?

 

Thanks in advance! 

Edited November 22, 2022 by TC_cruiser (see edit history)

[Hemi Dude]

6 hours ago, TC_cruiser said:

Howdy everyone,

 

I just recently purchased a '89 Auto TC- it's a pleasure to drive and very well maintained for it's age, but I am running into some problems with wiring. The second day I drove it, I got pulled over for having a third brake light out. I took it to my friends house and we got the third brake light housing out and rewired/rebulbed with fresh 921s and... Nothing. We're getting a current to the bulbs when the brake is pushed, but nothing is lighting up. We had them briefly turn on with the old (broken wires) but after splicing they wont work at all.

 

Does anyone have experience with this same problem, and what additional diagnostic information should I provide?

 

Thanks in advance! 

Your problem is likely at the 'GROUNDING RIVOT' on the circuitboard. It "looks" good but has likely an open circuit (poor connection)

 

If you want brighter illumination, install a set of LED bulbs.  Also no more grounding problems.

Edited November 22, 2022 by Hemi Dude
Spelling correction (see edit history)

[TC_cruiser]

Thanks for the response! I'll give that a try... Honestly replacing with LEDs was exactly what I was thinking- seems like it would save me the headache of having to fiddle with this thing down the road. Did you remove the whole bulb housing?

[Hemi Dude]

Just now, TC_cruiser said:

Thanks for the response! I'll give that a try... Honestly replacing with LEDs was exactly what I was thinking- seems like it would save me the headache of having to fiddle with this thing down the road. Did you remove the whole bulb housing?

Yes, remove it from an opened Tonneau cover, just 2 Phillips head screws, you can see the locations in the photo. Of course, the hard roof has to come off first.

[TC_cruiser]

I was referring to the metal thing that holds the individual bulbs to the wires, do those LEDs slide in the bulb holsters or did you replace the whole thing?

[TC_cruiser]

Oh wait I see you've replaced it. I'll do that! Thanks for all the help!

 

Edit: one more question, do the LEDs have to be rated for a specific power level?

Edited November 22, 2022 by TC_cruiser (see edit history)

[Garnet & Gold]

Eli,

Looks like somebody has already played with the internals.  Here is a picture of the factory lights. 

Bob (Got your app)

[TC_cruiser]

Hi Bob,

 

Yep, that's what mine looks like. I think I'm gonna take Hemi Dude's advice and just replace with an LED strip! Less bulbs, less headache... Just wish I'd had that idea before buying a bunch of bulbs 

[Hemi Dude]

If you look carefully, you will see that the 'crimped terminal' that the green arrow points to (-) is discolored [darker] compared the other (+) which is lighter.

That indicates excessive heat at the ground (-) terminal which causes it to sinks into the plastic bulb retainer and that creates the open circuit.

Trying to solder the ground wire to the terminal doesn't work either because it is NOT steel and the solder will not take.

A very thin machine screw will pass through and if tightened sufficiently, WILL provide the ground connection which was lost.

But the LED strip idea is a "Brighter" one.

[mensanguy]

Where can one purchase this LED device?

[Hemi Dude]

6 minutes ago, mensanguy said:

Where can one purchase this LED device?

I just searched on-line.  I bought the ones I got several years ago, they were very IN-expensive.  

 

[TC_cruiser]

We decided just to replace with LEDs. I got a set from Walmart, which turned out to be slightly too large. We removed the housing and shaved a bit off of the insert for the car, and now its working perfectly! 

[Hemi Dude]

It is great that you were able to install LED lamps in your stop lights, BUT they appear to light up amber because the LEDs light up ‘CLEAR’ which makes the brake lights look AMBER which is not correct for stop lamps 

Are RED LEDs not available?

[ghostymosty]

That might be a trick of the camera, the taillamps seem to do the same thing in this photo. Did he put the same LED's in the taillamps?

[TC_cruiser]

It's definitely the picture! The lights I replaced were white and the color is much redder in real life.