demotim00

On my '97 Ford Explorer the interior light keeps coming on & going off. It only does it if the vehicle off & it doesn't matter whether the key is in the ignition or not. It randomly comes on by itself & after a few minutes will go back off. It sometimes won't do it at all, at other times, it will do it 5 or 6 times in a row. The interior light functions like it should other than that. Any ideas as to what would cause it?

wrenchboss26

you may have a door switch going bad.

demotim00

I could be wrong, but if a door jam switch is going bad, wouldn't it also act up while the car is on?

shorod

It is reasonable to expect that you would also see interior light issues when the vehicle is running if the door switches were faulty. However, the door switches are a common issue (try searching the forum for "door switch" or "ajar") and would be quite to either rule out or confirm. Even if the problem were with the interior light dimmer switch, I don't see a correlation to key on or key off, so unless someone can point to a circuit that would explain operation only with the key off, I think starting with the door pin switches is reasonable.

-Rod

demotim00

Is there a way to test the door pin or door ajar switches to see if one of them is acting up, for I can either confirm it is one & which one it is, or to rule it out as a possibility?

shorod

The easiest way is via a professional scan tool that can access the GEM module. This will show which door (if any) is registering as being open. However, these scan tools are not cheap.

If you're comfortable with a multimeter/test light and wiring, you can probe the wires at the GEM to see if one of the door/liftgate switches is grounded.

-Rod

shorod

Pretty good Rick, but you might consider updating with a suggestion that a better alternative is to use an electrical parts cleaner followed by an electronic contact preservative. I've used Caig De-Oxit as the cleaner followed by Caig Presev-It in a couple of applications and only had to do it once, seems to be a rather long-term fix. I've used the Caig products on numerous consumer electronics with pleasing results.

I'm not a fan of the typical suggestion of using WD-40 or similar as they are not designed for contacts, and in some applications, can actually etch away the conductive material and significantly detract from the component life.

-Rod