I replaced the blower motor resistor in my Jeep after not even worrying about it for the last 3 years. I finally decided I wanted heat in the TJ again and started wrenching. I found that the temperature slider cable is frayed but I have it stuck on the warmest setting.

On the other hand, the slider controlling defrost, floor, mid, etc does not work. Defrost works great, but it will not cycle to the other types. It slides over and will turn to the "OFF" position, but it doesn't physically change.

But the real problem is the heat. It's warm while on the "LOW" fan speed and then fades to luke-warm after turning it higher, like on "MED-HIGH" or "HIGH". I've done a lot of searching and the only things that come up are resistors and blower motors. Does anyone have a clue what's going on? I was thinking thermostat, but I'm not having overheating issues. I suspect the heater core is clogged but not completely. Any ideas?

Oh, and I heard replacing the blend door actuator under the passenger's side dash will work.

I replaced the blower motor resistor in my Jeep after not even worrying about it for the last 3 years. I finally decided I wanted heat in the TJ again and started wrenching. I found that the temperature slider cable is frayed but I have it stuck on the warmest setting.

On the other hand, the slider controlling defrost, floor, mid, etc does not work. Defrost works great, but it will not cycle to the other types. It slides over and will turn to the "OFF" position, but it doesn't physically change.

But the real problem is the heat. It's warm while on the "LOW" fan speed and then fades to luke-warm after turning it higher, like on "MED-HIGH" or "HIGH". I've done a lot of searching and the only things that come up are resistors and blower motors. Does anyone have a clue what's going on? I was thinking thermostat, but I'm not having overheating issues. I suspect the heater core is clogged but not completely. Any ideas?

Oh, and I heard replacing the blend door actuator under the passenger's side dash will work.

Been here done this recently. Heater core gets plugged just enough not to circulate water, hence no real heat. I back flushed heater core and that helped a little for a couple days. I tried this back flushing about three times, then just broke down and put in a new heater core. New heater core is twice the thickness of the OEM. Heat isn't an issue now.

Well that sounds like a good solution. Which aftermarket core did you use? Ripping apart my dash doesn't sound very fun :(

On the other hand, the slider controlling defrost, floor, mid, etc does not work. Defrost works great, but it will not cycle to the other types. It slides over and will turn to the "OFF" position, but it doesn't physically change.



could be a vacuum leak, dont know if it applies to a tj.was missing the vacuum canister on my 90xj and wouldnt cycle till i replaced it.

That's a good point. I'll have to look into that.

X2 on the vacuum leak for the stuff only coming from the defrost vent.