Cosmo Kramer

On my way to SITM and a funny thing happened with my interior light. When I switch it on no light but the seatbelt chime comes on, my PRND32 indicator lights go out and my clock goes out??? Pulled the fuse for the interior light and it still does it. Happens whether I switch the interior light manually or open the door. Another symptom (maybe unrelated) was the chime beeps quietly when the car is shifted into reverse.

Any ideas??

JoeTaylor

My interior light, the one above the rearview mirror, messed up and started blowing fuses. Took it out and found that the plastic lens also holds part of the electrical wiring/connector. A plastic tab broke and the light, when pushed, was grounded into the steel of the roof.

The fix was to buy a Volkswagon interior light, same size and form factor, but completely enclosed. Replaced the old light fixture with the newer '90's VW one... everything is great.

Joe

Maleficio

Disconnect the other lights, narrow it all down to the forward interior light, see if anything changes. If yes, reconnect the lights one by one until the problem reoccurs.

Cosmo Kramer

OK home now. I have removed all 4 light bulbs and the fuse for the interior lights. The "phenomenon" continues. Wiring on all 4 light fixtures appears to be normal.

Cosmo Kramer

OK bumping it up here and giving some more info. My wife said she noticed that my reverse light weren't working when I left for my trip. Not sure if it is related or not. So far I have done the following:

Pulled all 4 interior bulbs
Pulled out fuses 12 (reverse lights, power mirrors) and 24 (Current Pulse-Tailgate, Interior lights)
Pulled out relay XXII for the reverse lights

Still when I open the door and the switch closes to activate the interior lights, my PRND32 light goes out and the clock shuts off. Is there anything else that could be powering this circuit? My interpretation is that something is removing the ground from the clock and the shift indicator when the door opens ie 12v is going to that ground circuit.

I am trying to read the wiring diagrams but it is really hard to interpret where the short could be.

Alan

Well its almost certainly a grounding issue... what have you worked on recently - anything in battery box/spare wheel well... check the ground there (behind plastic cover) - clean & tighten

Alan

Cosmo Kramer

Alan, is that inside that grey box? Haven't touched anything in there but you never know. I will take a look. I think the reverse lights go through that connection.

Last thing I did electrically was change a window switch. I looked through the center console and behind the radio, nothing abnormal. The problem arose while driving on the trip without touching anything.

Manfred

Yeah, ircc, the reverse lights do go thru the spare tire well connection.

Mike Frye

Ted,

I've been watching and hoping someone could help you out here. I know I was surprised to find how many connections go through existing switches or are grounded all in common when I had some interior light issues.

I wish I could help with some specific info but I will say that for electrical connections the only thing that works for me is to reduce the number of variables until I can understand it and then add stuff back in until I replicate the issue.

Maybe remove all of the fuses and add them back in (one at a time) until you find the one that lights up the wrong stuff. That might give you a path to check in the diagrams.

Cosmo Kramer

Last night I put a multimeter to the fuse socket on fuse 12 for the interior lights on the CE panel and I have no power to the fuse. The short is somewhere before the fuse. Gonna look at the wiring diagrams again. From what I can see the headlight relay powers the interior lights on an 85, but that relay is so complicated I am not sure what terminals power them.

Landseer

Fuse 12?
For 85 I'm showing that as the backup lights and mirror adjustment.

Ted, if you mean interior lights (door lights, glove compartment light, clock numbers, hatch & overhead lights, vanity mirror lights if equipped...) that would be 24.


That other stuff that's going crazy--- points to a harness short that's crossing the streams.

Cosmo Kramer

Opps my bad, yes fuse 24. I had pulled both to try and figure out the problem. That is funny you mentioned clock numbers mine is still running with that fuse pulled. Shuts off when door is opened. Might be something there.

Landseer

Well, one place that stuff comes together is under the console covers.

The lights for the clock (I think blue/black wires) and cigar lighter light are part of the group of lights that illuminate the dash (dash lights run thru the potentiometer).

The beeper is in that tangle, both physically and via connections at CE.

I've found a lot of messed up situations in the area at the base of the ashtray, radio, etc, leading back to the CE panel on the passenger side of the console. This includes some harness burns and not sure why, badly burnt ground wires in that run appearing to be ground zero.

Cosmo Kramer

OK did dome testing. Clock has power with the doors shut. I pulled each fuse individually with my multimeter connected to the clock power wire, still had 12v with every fuse pulled. That means I am getting 12v not fused to the clock/interior light circuit. Does this point to the spaghetti factory at the back of the CE panel?

Landseer

It could be wrongly wired or shorted in the console area.

But yes, as I read it, clock power is indeed fused. Clock light separate & is associated with dash lights; clock timekeeping power looks clearly to be associated with interior lights / fuse 24.

I'd unplug the E plug at the CE panel and see what happens to the clock ( it is fed via terminal E13, along with the glovebox light)

Regarding your question, behind the CE panel, maybe, maybe not. A melt in a distribution harness can backfeed other circuits, similar to a melt behind the panel.