alwaysjdm

iTrader: (1)

i installed a new radio because when i got the car it didnt have one. but my radio, interior lights, and my horn dont work. the lights in my cluster and up on the dash all work. ive looked at schematics and found that the radio and lighting are tied together in the same circuit. so i checked the fuse and it was fine. is this a common problem or does anyone know where i should go from here?

HAILERS

The horn can be worked as described in this link: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/horn-problem-828700/

Just get a piece of elect wire bare at each end. One end is put to ground. The other end is put in the backside of the CPU plug where the green/orage wire is in the top plug on the CPU. Horn should honk.

IF it does not honk (I assume the plug is on the horns themselves and the fuse is good, shouldn't have to mention that), then the horn relay Might be bad in the CPU. To prove it's the CPU most likely, just pull the top plug off the CPU. Jumper a wire b/t the Green/White and the Green/Red wires. Horn should honk if the fuse is good and the plugs are on the horns.

I assumed you turned the rheostat works on the switch or you tried turning it up/down and it had no effect on the interior lighting.

Interior lights not working might be the plug on the light switch. Pull the plug off the light switch and look in the plug for burnt/melted wires towards one end of the plug. I should ask......."do your side lights work, front and rear? Usually the interior lights are lost with the front and rear side lighting. Headlights themselves have nothing to do with interior lights or side lighting, so they can and will work normal.

If the tail lights work and just the interior lights don't, then the rheostat inside the switch itself is kaput. IF that's so, don't bother looking at the electrical plug.

I don't mess with radios. The lighting wire most likely does not power the radio itself. See the free, online wiring diagrams for the radio.

Interior lighting works like the attached jpg. The GW wire feeds the rheostat which in turn feeds all the items listed on the far right side of the page. It also bypasses the rheostat and feeds a RB wire that feeds the tail/side lights. So you can see that if interior don't work and side/tails do, that the rheostat is kaput.