[Brohammed]

I just bought a 98 Durango in really good shape except for a few things I need to fix. The biggest one is that the dash doesn't light up when I turn on the lights. First thing I did was go through the fuse panel, and found the blown Dimmer fuse. Replaced it, and it blows immediately when the headlights come on.

So obviously there's a short somewhere.

Unfortunately, I'm completely unfamiliar with this truck, and I don't know where to begin. Any suggestions? Are there any known components that blow out, any places where a wire would be likely to ground out, anything?

Grateful for any help.

 

[Brohammed]

Also, the speedometer only works reliably above 40mph. Below that, it's intermittent. Usually at 0, but occasionally it will jump up to 25 or 30 or whatever speed I'm going for a few seconds, then back down to 0. All the other gauges and warning lights work normally. Is it possible this is a related problem, or is it a separate one in the same location?

 

[RSQCali]

well in regards to the short if it is affecting your cluster i would start by looking behind the gauge cluster and around where the wire come across edges of the frame. And look behind the headlights make sure nothing pinched the wires.

 

[Brohammed]

I pulled the cluster yesterday, and didn't see any bare or pinched wires. The headlights do work, they blow the dash dimmer fuse when they come on. I may have been unclear. But I'll check there today.

I'm dreading the possibility of having to climb up underneath (or pull) the dash to trace wires.

 

[Brohammed]

Got inside the dash again today, and didn't find anything out of sorts. I thought there might be a pinched wiring harness under the tilt wheel, but nope.

On the plus side, I fixed the speedo/ABS light/Brake light problem.

I replaced the speed sensor on top of the rear differential, and both warning lights went off, and the speedo/odo started working.

In case anybody else runs into this problem, the part is $35 ($40 with tax) at Napa, and it takes about 30 minutes including fumbling around because you're not familiar with the vehicle. You'll need 13mm and 14mm wrenches or sockets. And if you have a hi-lift jack, that will help by giving you more room to work between the body and the axle (jack it up by the rear bumper or tow hitch).

 

[Brohammed]

Interesting new development...

Yesterday I pulled the crappy stereo that the previous owner had installed and put in my bluetooth/usb stereo. When I did it, I accidentally left a couple of wires bare, and while I was driving something periodically grounded out and kept killing the power on the stereo.

But while this was happening, the dash lights came on, albeit super dim. So. In the dash where the stereo is, there are two fat bundles of wires that were just clipped off (presumably they connected to the factory stereo), and one of those wires is related to my problem.

Does anybody happen to have a diagram of what all those wires are?

 

[Tymont]

Well, I'm at work so I don't have any wire diagrams with me. But something you might check for the dimmer fuse blowing is the headlight/dimmer module. It is a common problem of those going out over time due to over heating. Not to sure how much one costs though.
An easy fix, once you replace it is to drill a 1/4" hole in the AC duct directly over the switch module. This will help to keep it cool.

 

[Tymont]

Oh, I have a working one, but the headlight knob doesn't stay on. I guess you could glue it in place.
If you want it I'll see if I can find it and send it to you. If nothing else it would help you troubleshoot the problem.

 

[blazer4x]

Try looking to see if the dimmer wire that goes to the factory radio is grounded out. I don't know what color it is. Just an idea.

 

[Brohammed]

I was out in the truck fiddling with it tonight, and it's working now. But I'm more confused than I was before.

All I did to fix the problem was PULL a fuse. Not replace, remove. Once the "security panel" fuse (#1-20A in the fuse block) came out, everything started working normally - dash lights, the dimmer, everything.

Huh?

 

[Tymont]

Now that IS wierd. Did it stop working again when you put the fuse back? If so, then you've narrowed the problem to a specific circuit.

 

[Brohammed]

Now that IS wierd. Did it stop working again when you put the fuse back? If so, then you've narrowed the problem to a specific circuit.

To be honest, I haven't put it back yet. I'm just enjoying having lights that work.

 

[Brohammed]

Well, the mystery is finally solved. Setting aside all the other weird stuff, it turns out the previous owner joined a wire that's part of the dimmer/parking lights circuit to the negative ground of the stereo, which was grounded via the antenna.

So every time I plugged the radio into its harness, the fuses blew.

Everything is good now.

 

[Tymont]

Glad you figured it out. I hate trying to find electrical problems caused by someone who thinks they know what they're doing.

 

[Brohammed]

Glad you figured it out. I hate trying to find electrical problems caused by someone who thinks they know what they're doing.

Yeah, fixing my own screwups is bad enough.

 

[Tymont]

Yeah, fixing my own screwups is bad enough.

HAHAHa... I know what you mean.

 

[Big Red Dango]

I am having A similar problem

When I go to turn on my headlights my dash lights do not come on. I have checked fuses and changed the headlight switch