91 Explorer Interior Light Issue

[spidergirl]

Firstly, I'd like to apologize for my lack of general car knowledge. I bought a 91 Ford Explorer back in May and while she's (mostly) mechanically sound, she needs a bit of TLC so I'm learning more about how to go about car repairs and whatnot. (Thank you Haynes manual!)

Since I bought it, the interior light has never worked properly. I discovered that when the fuse in in place, the light stays on. All the time. Only way to shut it off, is to remove that one fuse. (When I bought it that fuse wasn't even in place)

I'm wondering how I can troubleshoot the issue. If I don't have it working properly, it's not that big of a deal, but if it's something I can fix, I'd like to.

 

[larrydd999]

This is NOT the place to be concerned about lack of general car knowledge, all of us started that way at some point. Looking at my '92 wiring diagram, one side of the dome light bulb is at ground potential, meaning it's electrically connected to the car body. The other side of the bulb (electrically speaking) goes to quite a few places before it connects to the positive side of the battery, any one of which could be a problem. My first suspicion would be one of the door switches has failed and is always 'on' whether or not the door is open. A copy of the wiring diagram (available for downloading on this site) and some patience should allow you to find the problem. It's also likely someone else on this site has already found and solved the same problem as you have.

 

[Centaurious]

First check to see if the headlight switch is working properly. If you rotate the knob while the fuse is installed will the lights go off?

 

[iLoveMyExploder]

indeed!

First check to see if the headlight switch is working properly. If you rotate the knob while the fuse is installed will the lights go off?

that's exactly what I was going to say

 

[spidergirl]

The headlights work, but I did notice the knob felt a bit loose. I'm going to have to look into that.

 

[Centaurious]

On these older Fords rotating the Headlight switch controlled the dash brightness. When it was rotated fully clockwise past a stop it also turned on the interior lights. Someone coming from the multi-function lever that controls turn signal, headlight dimmer, wipers, etc, are used to a headlight rocker switch and a dash dimmer wheel.

 

[natenkiki2004]

On these older Fords rotating the Headlight switch controlled the dash brightness. When it was rotated fully clockwise past a stop it also turned on the interior lights. Someone coming from the multi-function lever that controls turn signal, headlight dimmer, wipers, etc, are used to a headlight rocker switch and a dash dimmer wheel.

I hate to admit but that was probably my first WTF frustration moment with my Explorer when I got it. I was wiring up the stereo and checking things out. When I was all done, I closed the door and the interior lights stayed on. Took me about 10 minutes to realize it was the knob, I had fully rotated it into the 'click' position.