I just bought a 1998 Cherokee Limited last week and so far I love it. There are just a few small things that need fixing. The guy put in a new heater/ac blower motor, and when i turn it on, it only starts to blow air when i turn the **** all the way to 4. It works great, but just gets kind of annoying always having it on full blast. Also, my water temp gauge, sometimes it works and at others it doesnt. Sometimes it will work for a little and then the next time i look down its not working. Anything helps. Thanks

 

Sounds like your blower switch might be bad. You may have a poor ground in the instrument panel causing the gauge to read erratically.

 

Your heater problem sounds like a bad blower motor resistor, I've never seen the problem on the Jeep, but on the Fords I work on if the resistor controlling the blower fails it defaults to only blowing on high. Might check into that.
As for the temp gauge problem, try grounding out the connector going to your temp sender (key on), if the gauge pegs when you do this, your gauge and wiring are good and its most likely the sender. HTH.

 

I had the same problem a few months back and definitely sounds like the blower motor resistor. I have had 4 XJ's and had to change 3 of the 4.

 

That's definitely your resistor. It's located under the passenger side dash and has a plastic cover over it. They are between $20 and $30 at your local Autoparts store.

 

ok cool, thanks Ill check all of that stuff out

 

The BMR is the white thing in the middle of the photo:

 

Good photo

 

well i took it all apart and went to disconnect the connector and when i pulled it out, i found that the connector was melted. Any idea on why this would happen?

 

A previous bad blower motor will do that. Cut a good one off at the junkyard and splice it in to your harness.