Hi, I have a n/a 87 rx-7 GXL, and the interior electrical is a bit screwy to say the least.
First off, whenever I hit the brakes, with the lights off, several of the interior lights come on that should only come on with the headlights on. Also, the relays for the speaker amplifiers click, and the speakers come on until I let off the brakes, then they all turn off. second, for some strange reason, the radio cuts out whenever I hit the brakes or turn on the headlights/parking lights. I checked the CPU for cold solder points problems, and was fine.
The radio is not stock, but it's wired properly, so that's not the problem, as it didn't start until months after the radio was replaced.
Probably not directly related, the driver side window will go down but not up, I took the switch apart, and cleaned all the terminals, and checked the wires, and it's all good.
I tried swapping the CPU out of another nearly identical rx-7, same problem. I checked the fuse box, and a couple of fuses looked overheated, but not blown.
I know this is a lot to ask, but anything is better than not knowing.
If anyone has experience with interior electrical, please help.

 

have you checked the grounds? it could also be that some of the wires are touching at a point..hell it might be that you grounded to many things at one place.....most people seem to forget the ground...which is actually the cause of alot of problems

 

did you replace any bulbs in the taillights recently??? Sounds like you have the wrong bulb (a 1156) in the brake lights where a 1157 bulb should be.

 

I did replace a bulb recently, it happened after that, ( the lights turning on with brakes.) but the radio has been turning off with the headlights since I replaced it months before. I'll check the grounds though... Hoping that's the problem.

Thanks a lot guys.