Manfred

91GT (5spd of course). The HVAC lights, clock light, ashtray light, and security bar light are not functioning. Radio lights up as usual (obviously powered from different leads). Fuse #9 was blown. Replaced. Fuse blew immediately. Where's the short...

I recently had oodles of work done on the car, so the problem could be almost anywhere but I suspect it might be related to work done on the pod. The pod height adjustment locking lever was broken and was replaced. It seems to me somewhere back in my memory that the lighting for the center console gets it's juice passed on from the pod and potentially the rheostat. Anyone remember if that's the case? Should I be looking elsewhere for a reason the #9 fuse keeps blowing?

The other items done on the car: complete intake refresh, sharktuning, new bellhousing with all new parts other than flywheel, new shocks, AC refurb (front and rear), PSD pump replaced, all new vacuum lines, all new fluid lines (brake, fuel, power steering), new brake master cylinder.

Also, I think maybe the speaker wiring was redone but the other stereo wiring (power, grounding, etc) was not touched.

Any suggestions on where to start looking for the short?


Thanks,
Dan

Ducman82

check the rheostat , mine had issues and was blowing the fuses as well.

Manfred

Thanks; that was my suspicion. I'll start there.
Dan

Alan

Whatever you do - resist the temptation tp put in a bigger fuse - it wont help and may do MUCH harm - it is ALWAYS a bad idea.

Check what the potentiometer is connected to - may be incorrect...

Alan

Manfred

OK, here's what I know. I took out the rheostat (potentiometer), cleaned it (deoxit and stabilant) and replaced. Fuse blew again. Took out potentiometer altogether and fuse blew again (running out of 5amp fuses to trouble shoot with--need to head to store).

The fuse does not blow until I turn on the headlights.

Potentiometer appears to be connected correctly--there is a two prong keyed connector (only allows it to be connected one way). IIRC--there is some other two prong connector back there that is not used in US models (frequent question when people are poking around back there and find a connector not connected to anything). Maybe in the pod work the wrong connector got hooked up...

The wires going into the potentiometer are yellow and yellow with red stripe.

Anyone have any other ideas on where to look?

Dan

Alan

Those colors seem wrong - I believe should be Black & Black/Blue - check out the other connector.

Seemed you said it blew the fuse even without this in circuit though?

What else has been changed in the console/pod?

Do all the other pod functions work normally? is the bulb check working correctly - all illuminate?

Alan

Manfred

Hi Alan,
Yeah, the pod instrumentation lights up as expected and the bulb check function is working fine as well. And as you said, even if the connector was the wrong one, it should not blow the fuse with it disconnected...

Nothing else was done in the pod other than fixing the height adjustment lever but I'm not sure how much of the pod was disassembled to accomplish that.

Anyone know the routing for the center console lighting? The wire is shorting out somewhere between fuse #9 and the center console. If it goes through the pod first, then the short must be between fuse #9 and the pod as it shorts even if it is not passed on through the potentiometer.

Dan

Ed Scherer

That's the color coding for the wiper delay potentiometer wires, not the instrument lighting dimmer rheostat, which uses BK and BK/BL, as Alan already correctly mentioned.

If you disconnect the dimmer rheostat (to be clear: the one on the left side of the steering column, with BK and BK/BL wires on the connector), it doesn't leave much connected to the output of fuse #9. It's likely you've got a pinched black wire somewhere. I'll take a look at the routing of it on my car as best I can and get back to you. It does pass through connector T5, which, IIRC, is behind or somewhere near the pod.

Manfred

OK, well that at least explains why the rheostat hasn't been working. Wonder if the rheostat wiring is plugged into the wiper delay. We might be onto something here....

Thanks Ed. I'll report back...

Dan

Manfred

Oh, well, turns out mostly I'm just an idiot.

What's the saying, "Garbage in, garbage out"?

Well, turns out what I was calling the pod rheostat was actually the wiper delay. Stupid thing is hidden behind the wiper stick so I can't see the labels from the drivers seat. I was without the car for about a year so I forgot that the pod illumination dimmer is on the left hand side.

So, anyway, unplugging the wiper delay swich (and in fact really cleaning out the wiper delay switch) has no effect on my problem--go figure!

I've changed the original post, deleting the part about the pod dimmer switch not working.

I guess I will inspect the dimmer switch as it still may play a role in passing juice on to the center console...

Dan

Ed Scherer

Looking at the wiring diagrams for the '90 (I happen to have those at hand; your '91 probably isn't much—if at all—different with respect to this circuit), the only things powered right off fuse #9 before it's controlled by the dimmer are the "cigar lighter" light and one wire to the instrument cluster. So... if you disconnect the dimmer and the fuse still blows, then the short must be somewhere along that more limited circuit.

With the dimmer in the circuit, all the BK/BL wires are involved, which is all sorts of back-lit stuff (pod switches, various things in the center console, etc.)

Note that the dimmer itself cannot (in any way that I can see) be the cause of the failure you're describing. The dimmer rheostat ranges from approximately 0 Ω (i.e., direct short across the terminals) to about 6 Ω.

Manfred

OK, the plot thickens even more.

So, I took out the actual pod illumination potentiometer, and the fuse does not blow.

I guess that means either the potentiometer is the problem, or the problem is somewhere between the potentiometer and the center console.

Can I bypass the potentiometer by simply bridging the connector to see if the fuse blows? If it does not blow, that would implicate the potentiometer. If it does blow, that would mean the problems is further down the line.

Thanks
Dan

Mrmerlin

look for a pinched wire on the securing tabs of the pod .
next remove the console side covers right side first, and inspect the clock and lighter and ashtray wires for shorting

Mrmerlin

putting the dimmer wires together will route 12 v to the lights supplied by the dimmer

Manfred

OK--I'll poke around--not exactly sure where those are--I'll do a search.

I've done that--nothing obvious. One question though. Is there only one plug for the clock (with four leads)? The bulb sticks out the back and there's no direct connector for that, right? The bulb screws in and is powered by internal connections stemming from the four-wire plug, right?

With the pod illumination dimmer removed the #9 fuse does not blow and the ashtray light is coming on normally, but still no HVAC or clock light.