My heater worked perfectly fine untill i replaced my dash lights. I put all the screws back in and the next morning there was no heat. I figured it was the switch. So i took everything apart again and wiggled the wires that go to the switch. With the heater control assembly pulled out it worked. Then when i pushed it back into place the heat cut off. I tried fooling around more with it now there is no heat no matter what. It wont turn on. Do you have any clue what it could be?
I assume you're talking about the fan. The first thing to check is the fuse, since it came on and went back off it sounds like a wire or connection at the control panel, check all those. I tester is cheap and really helps in finding where the power is not reaching the switch.
If when you check the vacuum lines and find that, that is not the problem, take a look at the blower motor resistor. You have the old coil style in that year, you my have broken one of the coils that may have been just holding on. That could be you problem. just something else to look at.
If the blower is workng but only cool air is coming out, you may have unhooked the cables that open and close your heat/cool air flaps, You should hear the flaps open and close when you pull the levers, you can see under the dash the cables moving the levers, one in the center of the jeep, one on the passenger side firewall.