About 2 months ago I redid my interior and had the dashboard out. All was fine until about 4 days ago when I smelled an electrical smell and my gauges stopped working.

If I replace the fuse they tend to function until I start the car than it blows again. This is not always the case sometimes it blows immediately upon turning to run. However my speedometer and gauge lights continue to function.

I'm pretty sure I have a short to ground somewhere behind the dash. My question is what all runs on this circuit besides as I seem to recall the auto rear view mirror. Secondly can the gauge cluster housing short out? Being an electronic device I'm sure it can, but I thought I would ask. Lastly, any suggestions on testing methodology or where to start? I'm pretty good with electronics on these cars, this just has me stumped.

Thanks,

 

If it were me I would go back and remove the dash board and look for whatever shorted. I always check whatever was changed last. Also, if it was large enough to smell, there should be visible evidence.

A good method is to check positive voltage points/wires to ground using ohms or beeper mode and power off. You can also check for low voltage but with the situation you're in I wouldn't power it up until you find the short.

From what I recall, there aren't any wires to pinch in the gauge cluster so it's not as likely. I suppose something could fail internally as some components can fail and short out. Something like that should blow a fuse and save the circuit.

 

Thanks. I'll pull out the dash again soon and check whats going on back there.

 

Well I found two smashed/melted wires between the steering column and the dashboard. The question is what do/did they go to. They are tan and grey. For whatever reason mine have butt connectors on each and is cut off at the connector.

Any ideas what they were for?

 

most all grey dash wiring is back lighting lamps (cluster, hvac, radio)
the only straight tan wire that comes to mind is for the oil pressure gauge sender
there is an amazing amount of crap on the gages fuse for only being a 10a circuit

 

Good deal, glad that you found the short. Sounds like someone had possibly modified the wiring at some point. I'm thinking stereo, alarm system etc.? You said it affected the gauges earlier so that would be my first place to check. The oil pressure gauge that was mentioned makes sense especially from what you described.

If it's hard to tell where the wiring goes you can try guessing via schematics or by looking around and then verifying with a meter using the beeper, or ohm meter. The most common way is to use the beeper on the pinched wire and then on a wire you suspect.

Austinthirdgen or autozone have schematics online if that helps. They would also help to visualize where to look in case the circuit branches off etc.
http://www.austinthirdgen.org/index.php?pid=19

 

I appreciate the link and go to austin quite often. I probably should have mentioned these wires were molded together as a pair. But regardless I will try and trace them with the diagrams at austin. All the gauges worked before so these wires seem to be not doing much. I think I will heat shrink the wires to stop any future shorts.