Xeridae

Hey there. I just bought a 2004 with 50k miles (considerably low miles for the year with only one previous owner). I love the RX-8 but this particular vehicle is having some strange electrical problems that I am hoping someone can give me some advice on.

The car runs fine but it's interior door lights are stuck on. In addition to these lights, the rear and front-right overhead lamps also turn on when I have them switched to "Door". The front left overhead light works when pressed but does not turn on when switched to "Door".

Obviously the switches for these lights seem to think there is a door ajar however there is not as I have checked all doors and trunk. There is no door ajar indicator light on the dash either.

To keep the vehicles battery from draining I unplugged the 15A room fuse and this turned the lights off but this has resulted in some unexpected and strange results. The next morning when I started the car the check engine light came on and the center console would not power on or display anything until I plugged the 15A fuse back in.

I believe the check engine light is a false positive and I am going to disconnect the battery for 10 minutes and do the steering wheel reset to see if it resolves that but there is obviously some electrical issues going on with the car and I am not really sure where to start with it since it is behaving so oddly.

I did as much research as I could but did not come across anything similar to this particular problem. The car runs fine but these electrical problems are annoying.

Any advice is greatly appreciated and thanks.

RIWWP

iTrader: (2)

Yeah, leave the Room fuse alone, it is used for quite a bit.

I moved the post to Troubleshooting for you to get some more exposure, since this is not a common problem. I don't have an answer for you myself, hopefully someone else does.

Xeridae

Thanks for your help.

dannobre

iTrader: (3)

There are diodes in the Map light assembly that keep the circuit from back feeding...unplug it and see if the interior light and courtesy lights behave and your electrical draw is gone..then you will either need to check out the diodes or replace the map light with another unit...

Xeridae

Would the map light assembly/diodes also be effecting the lights that are attached to the inside of the doors?

dannobre

iTrader: (3)

It could cause they use a common ground...

Xeridae

Thanks. I think it is a grounding problem. I'll test it out and report back.

Xeridae

You nailed it. It was a bad diode. I am ordering a replacement map light unit. Thanks for your help. Kind of annoying how the whole thing is assembled in a way that either requires you to solder in a new diode or buy a whole new unit. Oh well.