Headlights don't work-can't find the cause

[mlelah]

My headlights don't work. There's no power to the headlights, or to the connector by the computer. The headlight switch seems to be working fine. Parking lights all work and high beam works. Fuses all OK.

I don't have the headlight wiring diagram for my '96 Cherokee (it's not in the Chilton manual), so I'm working blind here. Does anyone have a wiring diagram? There is a brown with black stripe wire coming off the headlight switch for the headlight but I can't figure out where it goes.

I did some searching and one possibility is the switch on the steering column. Someone wrote that the multifunction turn signal, wiper, dimmer, high beam switch could be faulty. But I don't see the connection between this switch and the headlights not working. Any suggestions? Thanks.

 

[ExJfever]

If the headlights work on high beam and not on low beam I would also suspect the multifunction switch.

 

[joe_peters]

Or two burnt out low beams--it happens.

 

[mlelah]

OK, my bulbs test out OK. But I've done further investigating and I made a mistake. The headlights work on low beam, but both the headlights and high beam don't work on high beam. Would this still be the multifunction switch?

 

[ParadiseXJ]

The high side of the relay sounds likely. Swap out the relay and see. Cheap. Otherwise it could be the switch on the steering column, more $$.

 

[mlelah]

OK, which relay? and where is it, thanks.

 

[ParadiseXJ]

On your 96 it's probably in the PDC (black box) and should be labeled on the lid. Since I don't have a PDC on my 90 it's up against the fender well on the driver side. Here's what it looks like on a 2000.

 

[Ryno]

check the connector down the drivers side by the air box. My old jeep shorted out there and was the problem for me. I just spliced the wire to bypass the connector and they worked for me fine. Might help, might not... but worth a look see. Cheers

 

[TiRod]

The headlights work on low beam, but both the headlights and high beam don't work on high beam.

If the High beams aren't working, swap the relay with another - try that. If no change, and the other circuit does still work - like the AC you possibly swapped with, then the relay is ok. They really don't often go bad, it's the controlling circuit that does.

That leaves the column switch, which is mechanical, too, and does wear out. IIRC that's a Chrysler column, not GM, either way, be very specific about make, year, and model to get the correct part. Any Chilton/Haynes will have the teardown procedure, but you can diagnose it by supplying power to the high beam circuit either at the column or relay to make the relay work. If the highs come on, it's upstream at the column.

 

[Mbjeep91]

Check the connector on the multifunction switch, i have seen many cases where the pin for the high beams gets loose and comes out of the connector, usually when in the column is tilted down all the way...

On one i only had to bend the clip on the female spade to keep it in the plug, but on my dads it was like the plug was molded wrong and there was nothing to keep the pin in, so i put some tape around it to make it fit snugly inside and then wire tied it to the next wire keeping some tension on it...

Hope this helps

 

[CharlesS]

On your 96 it's probably in the PDC (black box) and should be labeled on the lid. Since I don't have a PDC on my 90 it's up against the fender well on the driver side. Here's what it looks like on a 2000.

ParadiseXJ,

The PDC for the 97-01 XJ is mounted to the passenger side fender in the engine compartment and the Junction Block is mounted inside the passenger side kick panel... which I believe are the same on the 96 XJs....
The picture you have posted is the Junction Block which is inside the Jeep.
Need to check the relay for the high beams to ensure they are receiving control voltage from the directional control arm.....

 

[mlelah]

I appreciate your help but the power distribution unit for my '96 is totally different. I've put a bid on a service manual for my '96. It seems that there's a lot of info for 88-95 and 97-present, but not for 96. So I'll find out where the relay is and then check. Thanks.

 

[CharlesS]

I appreciate your help but the power distribution unit for my '96 is totally different. I've put a bid on a service manual for my '96. It seems that there's a lot of info for 88-95 and 97-present, but not for 96. So I'll find out where the relay is and then check. Thanks.

You do realise there were alot of changes made to the 96 model in preparation for the new body style which included body reenforcement, modifications to accomodate relocated parts and the new wiring bus for the ECM to monitor vehicle operations....

You will find your 96 more closely resembles the 97 and newer than the 95 and earlier....

 

[pcoakley5]

Problem on my 98' sounds very simular.
Bought a new headlight switch to change out. When I "forced" the connector loose, I found the inside of it had melted. Also found the original switch was good and the connector will work "sometimes". Other times I have to monkey with the connector to get the headlights to come on.
When I run with the lights on for about an hour, the switch gets pretty hot to the touch.

Does anyone know what causes the dash components to get so hot?
How difficult would it be to simplify the switch to a simple rocker or toggle?

 

[winterbeater]

Problem on my 98' sounds very simular.
Bought a new headlight switch to change out. When I "forced" the connector loose, I found the inside of it had melted. Also found the original switch was good and the connector will work "sometimes". Other times I have to monkey with the connector to get the headlights to come on.
When I run with the lights on for about an hour, the switch gets pretty hot to the touch.

Does anyone know what causes the dash components to get so hot?
How difficult would it be to simplify the switch to a simple rocker or toggle?

Best way is to search and find how to add relays to your headlight circuit. This should solve all your problems as far as overheating wires. It will make your stock headlights brighter and make future upgrades easier.

 

[CharlesS]

There is a reason why the factory puts 10A fuses for the driver and passenger side low and high beams; it is to protect the inadequate 16 or 18 ga wiring used for the headlight circuits...
About 10 years ago I installed a headlight harness with (2) 30A relays, (2) 25A fuses, 12 ga wiring to headlights and a 10 ga power wire.... to accomodate the increased headlight bulb wattage....
The aftermarket headlight harness will protect the factory wiring....

 

[TiRod]

X2 that - the headlight switch carries all the current for all the lights. It gets hot, it will melt down the connector, then the actual metal blades separate and come loose.

Not one of Detroit's better ideas. Basically, it's just cheap.

An alternate headlight harness with relays handling the heavy power to the headlights does a lot more for you. They can be built for less than $50, bought for more than $75, but they will work, and solve the problem. They also let you make the conversion to higher rated H4 bulbs later that seriously improve lighting beyond HID levels for a lot less.

 

[pcoakley5]

An alternate headlight harness with relays handling the heavy power to the headlights does a lot more for you. They can be built for less than $50, bought for more than $75, but they will work, and solve the problem. They also let you make the conversion to higher rated H4 bulbs later that seriously improve lighting beyond HID levels for a lot less.

Where can components or a complete harness w/ connector (loom) be purchased.
My connector has started the meltdown process, I'd like to change over before the fire

Thanks,