Hey guys, I have a question for you.

85 12a with no intrument cluster lights or tail lights with headlight switch on. All fuses are good, what else could it be? The brake lights work, just no illumination or tail lights.

thanks

 

ALL fuses are good?

Both of my 1st-gens came to me with the I/P lights dead. The first one was due to the PO wiring the cig lighter to the radio/light cluster fuse somewhat casually, allowing the wire to ground out at the cig lighter, blowing the fuse.

The second one was trickier. I was getting power into the dimmer module, but if I tried to bypass the module with a jumper (sending power out of it) the fuse would blow. Turned out that it's a 5-speed car, which has the wiring for the automatic's shifter lights down under the shifter boot. Well, the wires were connected to each other - direct short to ground. I unplugged them and bypassed the dimmer module - NOW we have lights! The short to ground had burned out the transistor in the dimmer module before the fuse blew - weird. I just cut the two power wiresoff of the dimmer module and taped them together, and removed the module altogether. This left a hole in the dash, which will be the perfect spot for a toggle switch for the relay for the driving lights which I will install - and headlights-switched power is right there! (I wouldn't drive the lights directly off of the I/P light wiring though...)

At any rate, the parking lights are on the same fuse, so if the parking lights work the fuse/wiring is still good up to the dimmer module. Pop it out of the dash and carefully pull it forward until you can get at the wiring, and check for power at the red/green wire. That's power going in... if that's good (probably is, if park lights work) then check for power at the red/blue wire, that's power going out. If no power there, the dimmer switch is your problem... but first jumper the red/green and red/blue wire together to make sure the lights work. If the fuse pops, you have a short to find... again most likely it's the two bullet connecters under the shift boot that are supposed to not go to anything unless it's an automatic. For some reason people like to plug them in to each other

Now... for the brake lights... they are on a totally different circuit. Does the horn work? They share the same fuse. If horn works, the only things that could be bad are the brake light switch (either bad or out of adjustment), the brake light checker module, or the bulbs themselves, or bad wiring/grounds.

 

Isnt there a fuse link around the dimmer switch? Or is that my 80 im thinking about?