1989 Jeep Cherokee lighting prob.
 

My head lights tail lights blinkers and turn signals don't work but interier lights work power windows work most of my gages work can't spell worth a ****!

How do i get an answer to my prob.

It may take some time for the proper member to notice your post. Give it some time and folks will chime in.

Just to clarify, you pull the light knob and you get working interior and gauge lights, just no headlights/taillights/blinker? Do you get running lights (sidemarkers, tail-lights) with the switch at "half-mast"?

Edit - Just have to ask - have you checked all your fuses (pull them and test the fuse even if it looks OK and also the connection at the fuse panel) related to these lights?

You can use the search tool to find old threads with similar problems. There are many threads re: the lighting functions, so plenty of stuff to read up on.

I would start by reading those threads and checking the recommendations and advice. You may find a good test procedure for your light switch and what wiring to check for faults.

No head lights no tail light no turn signals no blinkers no dash lights but turn head light switch for inter. lights and they work plus power windows work.

And no wipers no horn

I was told it was the brain what and where is it?

They probably mean the engine computer (ECU). It's a box with a gigantic wiring harness plugged into it, probably on the fender or firewall inside the engine compartment. On an XJ it's near the airbox on the driver's side fender (for U.S. models - Left hand drive). I'm not sure on a Grand Cherokee. On my 00 TJ Wrangler it's on the passenger side firewall.

However, don't jump the gun just yet - you need to do some research and diagnostics before you load a $200 +- part into the parts cannon.

1. Use punctuation.
2. State your problem clearly.
3. Tell us what you have already done to investigate or solve the problem.
4. Ask specific questions.

There is no "brain" that could cause this..............

I have checked all my fuses all my sellunoids changed head light switch key switch everything that could be done i did it has to be that computer.

What year is your Jeep?

It isn't, but do as you wish.

If Cruiser54 says it's not the computer - dude, it's not the computer.

If you're hell bent on replacing a part that isn't broken, bear in mind you need the EXACT part number replacement. If you can't read the part number you may be able to get a dealership parts/service department to look it up. I was able to with my 95, but on a 30 year old Jeep there's no guarantees.

Personally, I would politely ask Cruiser what diagnostic steps he recommends and follow them, but it's your Jeep and your money.

The PCM has nothing to do with that stuff. Im not as well versed in the older XJ, but my guess is that your grounds need cleaned up, or there is something wrong with the headlight switch/connector or even the wiring. Or all of the above. Wouldnt hurt to check the fuse box for corrosion, front and back. Whatever it is, its not the PCM.

Its a 1985 cherokee 4.0 automatic 4 wheel drive.