Here is where I am at with this issue.

I have confirmed the dimmer switch Rheostat functions properly, so it is not the mechanical switch.

Proof:
1. Measure with ohm meter, range is the same for both the switches I have.
2. The lights in the instrument cluster, radio and A/C display panels all dim properly.
3. Backlight switches in Radio function properly.

The lights which do not light up at all....all the rest of the switch backlights. A/C control module, hazard flasher, head light switch, fog light switch, heated seat *****, cigarette lighter backlights, head liner switches for dome and map lights, rear also, etc.

Here is the wire diagram in question.




Note: TO RADIO!

If this is the wire which sends current to all those bulbs listed AND to the Radio to control it's dimming then WTF? I cannot find another wire going to the radio that controls it's dimming, but either there is another circuit doing this or there is a common wire in the wire harness A19 that is broken going to all the rest of the lights, but not to the radio?

But that does not explain the short that takes out the fuse in the instrument cluster.

When I plugged in the new instrument cluster, those lights still did not light, but the fuse 15 no longer blew and the volt meter worked. I did not yet go through installing the new instrument cluster for fear that what ever took out the lights also will burn out that new one.



I don't think there is any other control module between these wires. See the diagram to L120 and L121 (storage compartment illumination and cub holder illumination) which go to bulb and to ground.


New finding, my side mirrors do not work.....just the folding-back circuit works.

Looking at diagram for that......guess what fuse goes to the mirror control unit? Fuse 15. LOL....same one that goes to the instrument cluster....


Now I am sorry I did not replace the fuse when I had the friggen drivers side door all unplugged. If there ends up being a short there in the mirror control wires that could explain the whole thing.

I am trying to trace the wires to the mirrors from the control unit to see where power goes to first...through the control unit to the mirror or to the mirror then back to the control unit - which is what I'd bet since this would protect the control unit if there was a short - i.e. control it by switching to ground.

Next step....take the friggen dash apart again, and unplug the drivers side door again, replace the fuse and see what happens. I am not hopeful since when I had the new instrument cluster installed (car would not run due to immobilizer) the volt meter worked and the fuse did not blow, but the lights still did not work. Not sure if leaving that new unit plugged in would have killed it too.

​​​​​​​Mike

 

When you have a direct short to ground it can be frustrating for sure. It can also cause current to "feed back" to parts of the circuit. An example is when you are connected to a trailer and you activate a turn signal. The result is you see both sides blinking at the same time, usually dimmer than normal (or one side normal and the other side dim). This is most often caused by a poor ground circuit between the tow vehicle and the trailer since the towing unit is the source of the power for the system. I have seen similar instances due to a poorly grounded light socket. I think you are on the right track with your isolation technique. Any component in that circuit that is back lit could be the culprit. Since the mirror functions aren't working, it would be a good starting point. With the door panel off, you could unplug everything inside the door, replace the fuse and plug in one component at a time till the fuse pops. Tedious but effective. I admire your persistence and wish you luck with this.

 

I unplugged drivers side door wire harness (four connectors and a pain in the ***), but fuse 15 still blew, unplugged passenger side door, ohm meter reads 18 ohms at fuse 15 and fuse does not blow. Points to fault in passenger side door perhaps. But display still says "Fuse" and Voltmeter still not working.

So both mirrors are now unplugged, perhaps there is a fault there somewhere. I cannot really see the interior lights (day time) so I am going to take a peak at night to see. Still does not explain the instrument cluster fault unless that internal circuit is fried by exposure to the prior short. May be time to put the transplant cluster back in to just see......

Mike

 

Is the mirror control in the arm rest on your car? It was in the center console on my '04 model. Reason I'm asking is that when you said the mirror control wasn't working it was kind of taking me in that direction.

 

Yes, but never spilled anything on it (if that is where you are going). LOL.

I confirmed lights still do not work....had to wait until it was dark enough to tell, too bright in garage today, odd orange orb in the sky today.....with blue stuff around it, sunny sky is odd for this area.

Mike

 

Wasn't thinking about a spill. Was thinking the mirror control might be the problem due to wear and tear thru normal use.