Courtesy lights acting strange

[Theodore]

Courtesy lights acting strange

So, we got the Jeep back after the transmission rebuild, and have noticed a weird behavior with the courtesy lights under the dash.

Was driving home from the Transmission shop in the dark, with nothing but the glow of the dash lights, when suddenly the courtesy lights came on, and stayed on for the duration of the ride home. We got home and they wouldnt turn off when I stopped the Jeep. And, stayed on when I opened and closed the door...

Our Grand Wagoneer is a 1990, with the wheel to control dash brightness, and on/off for courtesy lights. I played with that- nothing changed... it was late, so I disconnected the battery and gave up for the night.

Yesterday, I decide to take a look, and reconnected the battery, expecting the courtesy lights to be on. But, they werent. We took a run around town, messing with the switch, which seemed to work fine, when all of a sudden the lights came on by themselves, and I was unable turn them off with the switch. Hmm.

Went into a restaurant for 30 minutes or so, and when we returned, they were off...

Took another drive, and after a few minutes they came back on again. strange.

Came home and parked, turned off the car, they stayed on... locked up the Jeep and went inside. Set a 5 minute timer to go back out and check, and if on, disconnect the battery until I could get time to troubleshoot. They were off...

Not sure whats going on...

I am familiar with electricity, having rewired a few houses, but car wiring is still somewhat of a mystery to me. Any ideas what going on?

The funny thing is: we didnt see any of this behavior prior to the transmission rebuild, but I dont see what that has to do with this.

Thanks.

[babywag]

The 2 underdash lights are on a harness by themselves runs from passenger side bulb to drivers side bulb and only a few wires. Take a look maybe you'll find problem.

[nograin]

Maybe this will also help.

In general, interior lights are turned on by switches on the ground side of the lamps.

In other words, power is always going to the lamps. Anything connecting the ground wires will turn them on.

Power sources--------Fuse--------Lamps-----Switch----Ground.

This is how opening any of the four doors will complete the circuit.
Any of those switches to ground will do it.

It also means a wire missing insulation can touch sheet metal and turn them on,

[fsj454]

x2 nograin . Does the overhead light come at the same time.

[Theodore]

x2 nograin . Does the overhead light come at the same time.

Neglected to mention: the headliner is out, so there are no interior lights, other than the dash & the 2 courtesy lights.

Btw, am out of town this week, will be checking wiring this weekend.

Thanks.

[FSJunkie]

The wires that run to the door switches are probably chafing, pinched, or otherwise shorting to ground.

[fsj454]

overhead light

I think headliner dome light wires are grounding out. Because they are not hooked up and hanging with no tape

[FSJunkie]

That will do it.

[Theodore]

Thanks for the advice; am planning on taking a look this weekend once we are back in town. Will let you know.

[Theodore]

Found it! Following recommendations from the forum, first checking the sunvisor connectors, then the domelight connector, then went door to door to check each door open indicator, and nothing... Then, I remembered someone mentioning the rear dome light... but, there were no wires past 1/2 way back, or so I thought.

Happened to see a wire tucked into the upper rail on the drivers side.


Ran over to the drivers side and pulled the wire, and BAM! Bare connectors... Found it!


Thanks to all who offered advice! Glad to have this irritating issue fixed. Negates the need to disconnect the battery after every evening after a drive.

Hm- not sure whats going on, I cant upload pictures using the img tag.