Instrument Panel backlight intermittent

[ruiterman]

I just bought a 1996 Dakota SLT with 50,000 miles on it. Sometimes the instrument panel backlights don't work.

It appears that it could be temperature related. It seems so far that the first time I use the lights, they work, but if I shut them off and then turn them back on, the instrument panel lights don't work. All the other lights work, the radio backlight, the temperature control backlights, they all work.

I tore into it tonight and couldn't find anything at all that seemed like a loose connection anywhere. The fuse isn't the problem, I pulled it and then some of the other lights that did work, stopped working.

Is there any kind of a temperature type fuse in the instrument panel itself that could be the problem? I'm thinking about taking the instrument panel out, but I'm not sure what else to look for?

Any help will be greatly appreciated.

Thanks,
Ed

[ruiterman]

All right, I got it fixed. Here's what I did.

I figured maybe there was a problem in the instrument panel with a trace or something like that, so I pulled the instrument panel out to take a look. I applied 12 volts across everything and it worked fine. All the traces are exposed on the back of the board so I check them all carefully and didn't see anything wrong.

I then figured that since the board was so simple, it must be elsewhere. I went and got the dimmer switch and checked the resistance with an ohm meter. It varied nicely from 0 ohms to around .2 ohms or so( maybe it was .02 ohms, I don't remember but it was very small). I then got a hair dryer and added some heat to the dimmer switch. When I rechecked the resistance, it flopped around alot and never went less than .2 ohms ( or .02 ). In fact, when it should have been 0 ohms, it was .4 ohms (.04?). Anyway, if .2 is very very dim, you can see that .4 would be even less and appear to be off.

I bought a new dimmer switch and installed it tonight. It now appears to work just fine now. Time will tell for sure.

Ed