Hot car electrical gremlins.

I've noticed this the last two summers (July & August) with my car. When it sits out in the sun and heat or driving for a while in the heat, I get some electrical issues. Nothing major just little annoyances. If the car is cool or driving a lot in cool weather there's never these issues.

1. Brake light warning if I hit a bump in the road. Seems to happen more often as the car gets warmer or the longer I drive her in the hot weather. I can touch the brake pedal a little and it clears the warning. After I replaced all the bulbs with correct ones and cleaned all the contacts this doesn't happen as much as it used to.

2. Window switches wont work. This has just happened recently so I don't know if it really is problem or not. Car was sitting at a cruise in the sun and the window switches wouldn't work. Later that evening they worked fine.

3. This one is the most annoying and common when the car is hot. The rear hatch motor wants to keep cycling. Open the hatch (with key or switches at the front seats) and then try to close, the hatch pops up again and the motor keeps cycling a few times. This continues for at times, a lot. Then for some reason, after a while the hatch will stay down and the motor will not cycle.

Any ideas or experiences on these?

The rear hatch may be a relay that is getting hot but I am not sure how you could verify that and maybe should just swap it with another one.

The dash electrical problem is one that I have and I think it is the (pin grip tention) on the connectors/terminals.

I am going to pull my pod again and tighten the terminals on the wide flat connector's. That is normally the heat issue unless a modual is failing but I chase the easy/cheep fixes first.

Brad

Have you cleaned and tightened the grounds Rick? I was surprised to find the ones on my car above the CE panel were actually somewhat loose. Temperature changes, varying electrical loads and vibrations could easily transiently interrupt grounding. The number of electrical issues you have suggests they share a common cause.

Martin,
Yes I have cleaned most of the grounds. Particularly the CE panel grounds, the rear grounds behind the pass. side cover and a few around the engine. I've also cleaned the 14 points at the jump post. I know there are a couple grounds I missed though.

Brad,
The relay for the hatch motor is in the back near it correct? That may be the culprit, but it only over cycles when it's hot.

Thanks for the thoughts guys. I will keep this updated with anything else I find out.

My '84 has the same issue with the brake light indicator. In my case, I need a new pigtail. A friend following me along one night noticed that when I used my signal the brake light was actually intermittently flashing as a turn signal should while there was no activity at all from the marker on the lens. Rick, are you sure that you're noticing these gremlins more in hot weather and that it may not just be coincidental? How does it act in rain or humid weather?

KilnRed;5817 wrote: My '84 has the same issue with the brake light indicator. In my case, I need a new pigtail. A friend following me along one night noticed that when I used my signal the brake light was actually intermittently flashing as a turn signal should while there was no activity at all from the marker on the lens. Rick, are you sure that you're noticing these gremlins more in hot weather and that it may not just be coincidental? How does it act in rain or humid weather?

Austin; add an extra ground by the good light (direction you were signaling)
It is feeding back and grounding through the other bulb circuit.

I may be high resistance any where from the bulb socket (corroded) to the terminal on the ground side. sometimes its better to cut old terminals/connectors off and replace them.

Brad