Dome light question

[mwood65]

I went to put a dome light in my Cherokee and it is always on,


No door pins like newer cars that turn on the light when the door is opened so I guess it is only controlled by the headlight switch?



But no matter what I do with the headlight switch as far as turning the switch does nothing to turn off the light so ya think the switch is just broken?


It is a newer switch I just installed a year ago.


I could just get another light with an off/on switch on the light itself since the wires seem to be always powered.

[DarkMonohue]

I could just get another light with an off/on switch on the light itself since the wires seem to be always powered.

That's the smoking gun. Dome lights are typically wired with constant hot and switched ground. Pin switches in the doorjamb are usually spring loaded so that they close and complete the circuit by grounding against the body when the door is opened. I'm not sure there's a neat way to make it work with the door without a grounding pin switch.

On my J20, the dome light is turned on by rotating the headlight switch fully counterclockwise. I haven't checked the wiring diagram to see if it's switching hot or ground.

[Strode]

I doubt it's the headlight switch you replaced.

So, you put a new bulb in the overhead light, and it's always on? Maybe you don't see a door jamb switch now, but it came with one. The wiring to the door jamb switch is still there someplace under the A pillar, and if it's grounded, the light will be on.

Like DM said, the bulb is always 'hot' (supplied with 12v), and the circuit is completed by opening the door, which grounds the black wire & completes the circuit. The headlight switch can also be used to turn it on, by rotating it which grounds the wire to complete the circuit.

So what you probably have is that black wire that used to go to a door jamb switch, and is spliced with the other door jamb switches and then runs under the carpet and up to the overhead light, is grounded somewhere. I'd start with finding some door jamb swithes, and the wires that used to go to them, and start trying to put the circuit back the way it should be. You might find the grounded wire by trying to put door jamb switches back in.

[mwood65]

Ok. I checked the entire jam area around the door and there is no pin nor a hole OR plugged hole where one might have been.


The old dome light was so corroded and rusty I tossed it and bought a new one now that I am redoing the headliner.


The one I bought is just a universal dome light which should be irrelevant?


I also assumed it was the door pins till I looked and there was none so I figured that maybe in '74 the light was only activated by the light switch....which would be ok except that does nothing either.


So if it's hoit full time and switched though the ground maybe the ground wire is rubbed raw somewhere and grounding out along the roof or A pillar somewhere before it gets to the switch???

[tgreese]

Year, model, equipment? Have you traced the dome light circuit on the wiring diagram? Have you tested the circuit at accessible points along the current path with your multimeter? You have to look at the diagram and measure.

[letank]

its a 74, if no door pin, it is activated by the headlight switch. My 74 is the same, base model... no courtesy lights, no carpeting, only rubber flooring

[Tripwire]

check the wiring behind the seat it gets corroded mine was

[MysticRob]

The one I bought is just a universal dome light which should be irrelevant?

I would say apparently not. If no other changes have been made then the light swap has to be the issue here, wouldn't you say?

[mwood65]

Today while waiting for someone I was sitting there and started messing with the light...


I connected the 2 wires and started messing with the headlight switch and just turned it all the way left till it clicked and just rapidly clicked it back and forth a few times and the light shut off then turned back on and then on but flickered.



So I guess the headlight switch is bad, guess I will order a new one...


Thanks for all the input guys.

[DarkMonohue]

Today while waiting for someone I was sitting there and started messing with the light...


I connected the 2 wires and started messing with the headlight switch and just turned it all the way left till it clicked and just rapidly clicked it back and forth a few times and the light shut off then turned back on and then on but flickered.



So I guess the headlight switch is bad, guess I will order a new one...


Thanks for all the input guys.

Ah, yeah, that can happen too. My headlight switch was new eight years ago and never inspired confidence, and now is failing to reliably turn on the instrument panel illumination. Time to do some shopping and see whether they're all the same or maybe some are less crappy than others.

And definitely check the integrity of the wiring and connections at the switch. They're as likely to be wonky as the switch itself.

[tgreese]

Today while waiting for someone I was sitting there and started messing with the light...


I connected the 2 wires and started messing with the headlight switch and just turned it all the way left till it clicked and just rapidly clicked it back and forth a few times and the light shut off then turned back on and then on but flickered.



So I guess the headlight switch is bad, guess I will order a new one...


Thanks for all the input guys.

IIRC there's a rheostat on the switch shaft that controls the dash lights brightness. At the end if that is a collar-contact (the 'snap' at the end) that turns on the interior lights. Suggest you remove the switch and wash it thoroughly with a good spray on contact cleaner, and exercise it vigorously. Just the exercise may be enough, and you can try directing the spray up under the dash. Will help if your aim is good.

[mwood65]

.........and you can try directing the spray up under the dash. Will help if your aim is good.

The wife says I only hit the toilet 30% of the time when peeing so I guess my aim isn't that good.

[rang-a-stang]

The wife says I only hit the toilet 30% of the time when peeing so I guess my aim isn't that good.

BBWWAAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!!!
My 17yo son's aim is about the same!