Originally Posted by Darthbaker (Post 7974713)

We almost have our 72 K5 ready for the road....

I have located a few lighting issues that i'm going to start troubleshooting tomorrow. I felt it might be best to see what everyone thought might be the problem on the located issues and work everyone's else ideas if and when mine run out. lol

Keep in mind this K5 is stock and none of the wiring has been hacked on. So with that being said... everything works as it should except for two small issues.

1. Right rear running taillight won't work. Blinkers and Brake work great.
(I'm thinking a ground and since its a super simple harness if it is a wire I should be able to find it easy).... Might be a possible socket ground issue?

Using a little deductive reasoning. One brown wire supplies power to both tail lights. Everything is good back to the left tail light.

2. Right brake/blinker (same wire) works = good ground on right socket.
Whats left, the connection wire from left tail light to right, or the right tail
light filament in the bulb.
3. Check the wires from the left tail light to the license plate light to the right tail light. Notice in the diagram that the two brown wires are spliced together at the rear harness connector, and the right side feeds only the right tail light. Yours may be like this or it may feed off the left tail light.


Attachment 1664240





2. Right turn signals will not work, side marker & front. Running lights work fine on the Side marker though. (I'm praying it's a ground issue for the front , but might be in the column turn signal switch for the side marker...)

The turn indicator in the dash cluster is powered by the front turn signal wire, if it works then the turn signal switch is OK. But a power check at the column connector, on the dark blue wire, would still be in order, to make sure.

The marker light blinker is wired from the front signal, so it will probably work when the front is fixed. The marker light works with the tail light wires so the bulb socket ground is probably good. The front and rear parking lights are two separate circuits off the headlight switch, so don't confuse the two by thinking that the right rear doesn't work, therefore the front could be the problem or vice versa.

Here's the circuits.


Attachment 1664242


Any other thoughts or insights would be much appreciated. Yay wiring issues

Start with the simple stuff, check the bulbs and the socket grounds then the wires. : )