I have a 95 Cherokee and the low beams do not come on. The high beams work, as do the running lights. I went to the junkyard this morning and got another switch. Before I began pulling out the existing switch, I tried the low beams and they came on. Went to try the low beams again tonight and they did not work.

There is a small amount of voltage at the low beam terminal at the headlight when the brights are on and none whatsoever when low beams are switched on. Also, the metal just behind front of the switch gets extremely hot when the switch is plugged into the wiring harness for a few minutes (regardless of whether switch is on or not). I don't have a wiring diagram yet, my Haynes is in the mail currently. I made sure the ground on the back of the switch was connected. Tried the jy switch and got the same results.

I thought maybe the ground for this circuit is loose (don't understand why the brights would work though) but I don't know where this particular ground is located in the vehicle.
Any ideas?
Thanks.

 

Check the bulbs to make sure there in right and check the wiring

 

The ground is there to operate the interior lights when you rotate the switch, it doesn't have any effect on the headlights.

The metal just behind the front of the switch can get hot if your interior lights have issues, that's where the dimmer rheostat is located. Do they all work normally?

If your high beams work but the low beams do not, check the high/low dimmer switch and the wiring between it and the headlamp sockets. I'd say your dimmer switch or the associated connector has gone south If I were to take a guess.

 

try new headlights.

it wouldn't be the first time someone had posted this to find out it was only burnt out low beams.

 

Dimmer does work normally, I suspect the hot switch is due to the cabin lights being on constantly while I was working on this. I checked the switch this morning and it was cold. I have already tried new headlights with the same results. Does anyone know where the headlight circuit grounds? I have since learned the ground on the back of the switch is for the cabin lights only.

The high/low dimmer switch, is that separate from the headlight switch? If yes, where is it located? Thanks.

 

Dimmer switch and ign switch on top of steering column down by the firewall.
Also under the air cleaner box is a plug that feeds all the lights in the front. It likes to get corroded and crap out. But if it's both low beams and their the only thing affected I'd look at the dimmer switch first.

 

Did you check the fuses in the junction block (not the PDC)? Should be 10A fuses...

This response based on my weekend experience on my '99 - I know yours is a few years older but I expect similarities.

BTW: Headlamp grounds are common to both high and low beams. If your high beams work then your lamp grounds should be good.

 

Just to close out the thread, it was the dimmer switch. When I pulled the switch out of the harness, the brass cylinder the harness screws into had detached from the switch. My guess was there was not enough tension to keep the plug seated. It also looks like some type of conductor though. Word of caution to future readers of this post. I needed Torx and Star bits to unmount the swtich from the column. Hopefully I can save someone a late night trip to Harbor Freight. Thanks for all the help.

 

this post is old but quick ?. can leave steering wheel on , when removing dimmer switch?

thanks up front.

 

On my 97 ZJ you could just remove the column cover. The ZJ also had headlight relays in the PDC.

 

Sorry to dig up this old post again but I am having trouble with the same thing. First thing I will do is give the run down of everything I've already tried and hopefully someone out there has a fix, so here we go. I've checked as many fuses as I know of both under the drivers side dash along with the box underneath the hood. No blown fuses. I have now replaced the dimmer switch under the dash on the column along with the ignition switch in that same location (side note, finally got my turn signals working again without having to wiggle the key), I've replaced both headlights to no avail. Ive had the steering column just about ready to pull out short of 3 bolts which at this point I think is probably easier than dismantling the whole thing. The only thing that stopped me from doing that was fear of just getting the same problems with a different one from the junk yard. I saw that someone posted on this thread about checking voltage to the lights but didn't see a response on the outcome. Any help or guidance would be greatly appreciated. UPDATE. I have now checked and thoroughly cleaned the connection under the air box with no success, still no low beams. Only thing I can think of now is that I either missed a fuse somewhere other that the 2 fuse blocks or I have a wire rubbed thru but I dont even have a clue where to start with that.

 

whenever chasing loss of lights, I use a test light to detect 12V, or lack of

I cant see anywhere in this thread it says to add relays for headlights

imo, this is virtually essential. otherwise you will eventually fry your switch (and they will be brighter)

 

I've already started with the test light but I haven't found a wiring diagram for that plug under the air box yet to see what should have power on low beam. As for the relays, Ive never heard of adding relays to the lighting system. Never had problems with the old switch. Just replaced it to cut out another possible failure in the circuit. The old switch was still good. Ive already done it with the heater/blower fan but not the headlights. I've seen other people change out the steering column for various reasons and at this point Im about ready to do that to eliminate another possible failure point. From my experience at this point it looks like its easier to do that than tear down the whole column and rebuild it.

 

Have you downloaded the FSM, complete with circuit diagrams, wiring colors & connector diagrams..hard to troubleshoot electrics without that

just about anything can burn up without relays

the switch is the most common point of failure

 

There is a plug-n-play update headlight harness that just plugs into your original harness at the passenger's headlight plug and draws directly from the battery with 2 relays and it's own fuse. You can get them on Amazon or E-bay. Your original wiring sends all the current for the headlights thru the headlight switch and dimmer switch.