My XJ heat is not work, blower works air is pushed in all the right settings and engine temp is steady at 190-210f. I recently purchased this and it’s been sitting 3 years so expected some sticking of things.....still chasing an intermittent loss of power/backfire issue which I think is related to O2 sensor or pcm...still checking old threads. Strange thing before power loss and lurching starts, all gauges go dead and the air bag light comes on.....I’m getting the replacement instrument cluster connector and have the TSB on the replacement so expect the gauge issue to be sorted.
it is winter in Maine so if the tstat isn’t working it’s possible I wouldn’t see a high engine temp. What’s the next logical thing to test/replace ?

 

"What’s the next logical thing to test/replace ?"

The blend door. If you are up to operating temp on the engine, first check the heater hoses under the hood, both should be HOT, but one is hotter then the other. If they are hot, the problem is your blend door. Its located under the dash just to the right the console. If funds are tight, you can probably take it apart and free it up and it will work fine. I bought a new one, then took my old one apart and got it working in short order.
Good Luck!

 

Look for a vacuum leak as the reason for all of your problems.

Not guaranteed, but it's the prime suspect, and the first place to look. It's usually a very cheap fix, once you find it.

 

is it the actuator for the blend door or door itself? Rock auto states you have to cut something open to replace the door. I’m going to put my hand on the actuator and then turn heat up to see if I can feel it trying to work if it does then I will free up or cut open to replace door. If I’m missing something pls shout out. Thx

 

I would check the hose temp first............

 

In regards to the instrument panel and related problem, I hade the same problem with my '98 Cherokee and '98 Voyager and found it was nothing more than poor ground connections under the dash.

 

My apologies to the OP. I meant the actuator. You can check it if you have long arms.... Just put your finger on the center pivot and move the heat control ****. Or you can take out 3 or 4 screws and check it while still connected but not attached. I had to remove the actuator (figured it was bad) as I wasn't coordinated enough to feel the pivot and turn the ****, I guess. If the pivot does not move, just unplug it and open it carefully. Apply 12 volts to it and manually assist it to start moving and it should work fine after that. Dry grease or packed grease is what usually stops it.
But to save overlooking something, make sure your heater hoses are both hot. The blend door actuator/motor is electrically powered, the vent selector is vacuum operated.

My only caveat is that my advice is for the 97 and up models. My experience with prior models has been years ago and I didn't save those practices to memory..........or I forgot!

 

One heater hose is much hotter to touch than the other.....does that mean tstat replacement?

 

If you’re up to operating temp your thermostat is fine. Your heater core is stopped up. You can try back flushing it. While the system is open, flush the radiator to. 3 years is a long time sitting. If anything else in the coolant system is suspect, now is the time to replace it. Especially hoses. Hopefully you can get some flow through the heater core.

 

Coolant levels good as are hoses etc. will definitely try to back flush core and flush radiator
thanks and happy holidays

 

are 87-90 and 90-96 blend doors electric too or cable operated?

 

Cable

 

I thought they were satellite.....