The blower motor isn't getting electricity. Maybe the resister relay?

The Power Distribution Center under the hood contains relays & fuses, it's a black rectangular box. Go on here and fill in your info and Wiring Diagrams. >->Jeep Informational Center at Morris 4x4 Center
When it opens, scroll down to page 8W-10-1 listed in the upper right hand corner of the page. That is where the PDC info starts.There is a list/diagram listed showing what it contains/covers, and the diagrams follow, or can be looked up on the page listed.
Hope this is helpful, and it's Free.
Dan

The pre-'91 xj's actually don't have that fuse box, but they do have relays with a cover there.

The blower motor is easy to replace if its the problem. I got one for about $28. Under the dash on the passenger side is the resistor, its really easy to get to under the glovebox. It has a plastic cover held on with 2 phillips head screws. Its grey or aluminum colored and has resistors that look like springs.

When you turn it to heat, defrost or vent setting does it blow air. All the resistor does is change the resistane to the blower motor thats how you get the different blower speeds, when the resister goes out, usually only one speed will work and thats the fastest speed. They do this for safty reasons so you can still have defrost. Get the multimeter out and start voltage dropping the whole blower circuit if the blowers not functioning at all. In the fuse box theres a 25 amp fuse for the blower motor. As far as a/c goes yes you have the R12 system and if you do anywork to your a/c system bring it to a shop and have them recover it for you to be safe but before going to the a/c keep it simple and check that blower motor and keep us posted. good luck.

Thanks alsj, I tried to pull the fuse out with my fingers and couldn't I have to use a pair of pliers to get it. Looks like it melted itself to the fuse block it's self. Hopefuly this is the problem. I checked to see if the ac compressed was getting power and it wasn't. If I touched a wire to the battery and to it then it tries to kick in. I replaced all four relays under the hood but it still doest turn on. I'm gonna go to The auto part store and get a new fuse so I'll keep you updated.

We have a functioning blower now but it's not cold. The compressor still won't kick in. I'm stuck here. I replaced the relay soaybe it needs recharged?

Thats great that the blower motor is working. However keep an eye on it, fuses pop for a reason and it may be a good idea to check the wires coming out of the blower motor to make sure they have no knicks in the wire insulation. I had a knick in mine once and the bare wire kept rubbing against my fender causing it the short and blow my fuse. Far as a/c goes check the grounds to the compressor if the compressor isnt coming on. If it is and its just blowing warm air, then most likely you may need a recharge. Just to warn you R12 refrigerant is expensive and to have it done right you should have a shop recharge your system and it may get more expensive if you have a leak somewhere in the system. Wikipedia isn't the best but they sum it up alright for refrigerant, take a look at the link to learn more about refrigerant.
http://en.wikipedia.org/wiki/Refrigerant

Ok I'll take the grounds off and wire brush them incase any corrosion is blocking it from getting a full connection. It's not turning on at all. So I don't think I have to worry about the r12 right now. Thanks.

Well the grounds are clean. It still won't come on. Any other ideas?

Is it true that compressor won't engage if it needs to be recharged?

have you checked the a/c clutch relay? Its the first relay towards the front of engine in the relay block.

Yes, most auto a/c systems will not kick in if it needs a charge, it has a low pressure cut off switch to prevent damage to the system if low enough. You can take off the cut off switch plug and jump across the switch with a wire and see if it kicks in, if so, either needs a charge or needs a new low pressure cut off switch. was it cold last time it worked? if it works on bypass, is it cold? and check the sight glass for bubbles.

also do a search for compressor shims fix. there is a magnet involved in the magic that runs the compressor, and on older systems it can get gunked up or weak and removing a shim from the system can get it to work again. saw a post on this eariler in the week.

If it needs recharged it should still be getting power right? I put a light tester on the neg. battery terminal and the other on the wire and the light didn't turn on. But if I put the end on the positive batt terminal and the other on Te wire it lights up. Idk if thats ok or not?