View Full Version : electrical issue with FUSE 18

03-31-2003, 11:32 AM
I have had this problem since I bought the car and think the old owner must have cut somthing on a radio install. The car is an 89 SC without the auto heads lights or keyless entry.

Nothing that FUSE 18 powers is working. I get no interior lights with either door open (checked both switches are good) but they do work with the head light switch. Power mirrors are out, map light etc all not working. I can get any one thing to work by jumping power to the power (green/yellow) wire.
What I don't understand is I get about 0.66 volts on the power wire. I jumped power to the map lights and they work but nothing else. I also jumped power to the power mirrors and got the same result, mirrors worked but nothing else. It seems to point to a junction where the power is distributed to all of the devices, but I can't explain the 0.66 volts.

Does anyone know where the power for this circuit braches out from. I don't want to rip into the dash with out a good idea of where to look.

I have the Helms shop manual but it doesn't give any electrical diagrams.


03-31-2003, 02:04 PM
I'm not sure what fuse 18 is b/c I'm looking at a 93 diagram. But in the fuse box under the dash, "INT LPS" 15amp controls the mirrors, courtesy lights, main light switch, engine light, Day Time running Lights, trunk light, console light, glove box light, intument cluster, visor lights, dome lamp. The only #18 I see is for the electronic cluster. It shows a LD/Y for the wire from the power block to all of these lights & switches. I guess you'll have to check them all for shorts. I hope this helps, good luck.

04-01-2003, 01:02 PM
That's the right fuse - nothing that it goes to has power and I don't see continuity between devices. Somewhere in there all the wires connect together. I just need to find out where the junction is.


04-01-2003, 01:11 PM
it sounds like someone was cutting lines, trying to find a short. You've probably inherited an old problem and it's going to take a lot of point to point checking to find the breaks and the short. :(

04-01-2003, 01:49 PM
I know that the person who had the car before me had a aftermarket stereo system and put the stock stuff back in.

None of the wires at the radio are cut but I haven't looked behind the dash. From under the dash evrything looks intact.

Do any of these circuits run to the rear deck for the keyless entry? (the keyless entry module is in the rear deck right?)
I don't have the keyless entry, but it wouldn't hurt to look everywhere the wires go.

If I had a diagram of the harness, I could easily look for the best place to start ripping stuff apart. I don't want to pull the dash and take the chance of sqeaks and rattles if I can check other places first. My GM (cavalier) rattles like a b1tch from a dash removal, but then again every GM I've owned compained about being driven :D. Maybe it's the way I drive


04-01-2003, 03:31 PM
The keyless entry modual is on the left rear 1/4 after the wheel.
All of those wires do join at splices #S337, #S332, # S333, #S334, #S902 and so on, but the wierd thing is, my 93 Elec/Vac manual say that most of those splices are located at the "Window regulator jumper harness, below LH door sill".

04-01-2003, 03:59 PM

That's where the left over radio wiring looks to be run. I'll have to check that out.

Also need to find a electrial manual for it.


04-01-2003, 04:42 PM
I just ordered the EVM - 38.95 delivered. I was shocked that it was in stock.

So now that I have the shop manual and the EVM, what's going to go wrong that's not covered by those:mad:

Thanks again for the info - hopefully I can get this fixed before the EVM comes in.