86 Turbo Z wiring issue

[Lee'sdaytona]

Greetings,
I would have posted this in my project thread, but it doesn't seem to get much attention anymore.
Anyway, 86 Turbo Z. Power to radio only works when the door is closed (dome lamp off). When you open the door, the radio and Navigator go out. Therefore, the Nav/radio will not keep time. When I use the blinkers, the digital clock lights blink with the blinker. When I hit the brake pedal, the lights on the digital clock go dim. Power window only works when the door is closed. The brake lamps are dim.

First answer is always to check grounds. I checked the major one under the hood to the engine block, and the fuel rail to firewall, and the little ground by the battery tray. I checked one by the driver's kick panel.
Is it possible that a faulty head lamp switch could do something like this?

I remember my 87 daytona would randomly make the door chime go off while driving with the headlights on and back then replacing the switch fixed that. The 86 I have now the T-tops leak and there was some signs of water near the switch area.

Any ideas?
thanks!
-Lee

[supercrackerbox]

It wouldn't hurt to try a different headlamp switch. The way the factory directed all the lighting power through them wasn't the best idea, and I've seen a ton that have turned black and melty over the years. Beyond that, it really sounds to me like a short to ground somewhere. Start with your door switches and just start going through the wires looking for chaffed or broken wires.

[Lee'sdaytona]

For what its worth, there is a grey wire with a yellow stripe that has an eyelet put on it, that someone hooked up to one of those bulb style oil pressure senders. The original factory oil sender was still there, but the spade connector broke off. I replaced that and hooked up the grey oil pressure sender wire (no stripe). So the question is, what is the grey with yellow stripe supposed to be for? This would seem to me to be a semi-short to ground, no?
-Lee

[supercrackerbox]

I checked on my Charger tonight (also an '86) and the grey/yellow wire also goes to the bulb sender. There should be two oil sending units on your car, one for the gauge and one for the warning light.

[marc]

Okay, the first problem with the radio going out, when you open the door, try removing the time delay relay in the fuse box. (It's a round can, sort of like an old flourescent light starter.) See if it stops. It's hard to tell what's wrong with something when I'm not directly there, but it sounds to me like you have a power distribution problem. I'm going to guess it has something to do with the fusable link 18 gauge gray under the hood. I think the first step would be to check the voltage with a volt meter at the fuses for the dome light, stop lights, and so forth. Turn those circuits on and see if the voltage drops. If it drops more than on one fuse, the problem is before the fuse. As an example, if fuse #5, 6 and 7 all lose voltage when activating one circuit, the problem is before it, most likely a splice at the fusable link or the bulk head connector in the firewall.

The '86 Daytona (I know this because I have an '86 Turbo Z) has both an oil pressure gauge and a warning light. The gray wire goes to the oil pressure switch for the light, and the gray/yellow goes to the oil pressure sending unit for the gauge. Good luck!!!