Originally Posted by zzzzzeke
I noticed my dash lights were a little dim this morning. When I hit my brakes then brighten up. Also, when the car is off and I hit my brakes my dash lights and parking lights come on. This sounds like a wiring issue.
Only thing I can think of is that I've been messing with my tail lights lately. I've had to go through the wiring because I was blowing fuses and grounding out.
I'm not too sure what this is, but I might not mind the gauges coming on before the car starts??? It'* kind of like my sisters regal that the gauges go on when the door opens??
Why, are you fixing your sister'* car as well?
Okay, I'm almost positive you have a bad ground in your taillights. When you step on the brake, current flows down the wire to the brake lamps, can't get to ground, and doubles back through the taillamp/parking-lamp circuit, which shares the same ground connections. Current comes back up the taillamp wires and circulates through everything connected to them, including your dashboard lighting, and there you are.
1) So, first have an assistant get in the car, turn on the taillamps, then step on the brake. Any light that goes out when it'* supposed to get brighter is your culprit: it'* getting voltage on both tail and brake circuits, but has no ground. When _one_ of its circuits is hot, it can use the other as a ground path and light the bulb. When _both_ of its circuits are hot, current has nowhere to go (since the ground path is broken), and the bulb goes out.
2) Remove the offending bulb and swap it with another brake lamp that'* working properly, and re-test.
2a) If the symptoms move with the bulb, replace the bulb.
2b) If the symptoms stay with the problem socket, no matter what bulb you use, check its ground connection: it apparently doesn't have one.