I just got a 1990 GXL RX7. I installed my after market stereo and now the door light and the radio power flash. The radio will not turn on cause the power surges on and off. It goes the same way with the door light on the dash. Does anyone know what this could be or how to fix it?

 

You may have wired it up wrong. A common mistake is connecting the head unit's ground wire to one of the car's wires. There is no ground wire in the stereo harness, you connect it to the chassis. There's a 10mm bolt in there somewhere that makes a good ground point.

 

There is a wire on the stock radio's harness, that is Black/Red ( a three wire plug if memory serves).

It is not a gnd wire even though you might have ohm'd it to gnd and saw point 2 ohms or better (0.2 ohms). That wire leads to the light switch on the column and what your reading is gnd through a filement in a light bulb.

I'd bet several headlight switches have gone south doing that.

That's my guess coupled with the info from the above post.

So if your using that Black/Red wire as a gnd, stop and find another real gnd. The black wire at the cigar lighter is a good place to look imho.

 

i used the correct ground and ground it to the 10mm bolt next to the shifter. I am still having the problem of the flashing power and flashing door light.

 

I just had this issue last night and the forum solved it! Hooray for search!

GG