electric issues related to heat
 

Jeep Cherokee Xj 2000 6 cylinder.
My Jeep has no heat. I found that the "blend door actuator" was not working when plugged to the car, but was working fine when hooked up to an external 12v batteri. The blend door is not stuck, it moves freely by hand. So what could be the cause of this?
While messing around trying to find the problem, the heater blower wouldn't work suddenly either (was working fine before i was trying to find the problem of the actuator not moving). I noticed that the fuse n. 25 was blown, so i replaced it, but as soon as i turn the key the fuse keeps blowing again?! I tried swapping the blower relay but no luck.
So what could the problems be? and can they be related in some way? summary: Blend door actuator not moving, heater blower suddenly dies to.
Its getting cold, so any advise is appreciated.

for starters, disconnect the battery, remove instrument panel, remove the heater controls and inspect the wiring to the blower switch. Sounds like a burnt wire or chaffing to cause a ground short.

Already did. I inspected all wires that i can see behind heater controls, behind glovebox etc. I heard it was an common problem but no burnt or melted wires to be seen on mine,

Well I cant remember off the top of my head what years have the heater control valve and which ones dont, but here is what it looks like. Maybe it is not opening. And I cant see not having heat causing the blower motor to stop. Prolly seperate issues if I had to guess. But starting with the HCV is a decent place to look.

https://www.cherokeeforum.com/f2/new...s-again-29877/

Scroll to post #7 and see the picture, and how it should look when "open" and letting heat into the cabin.

Ok so you have a 2000, so you wont have one. It was a good idea though.....

https://www.cherokeeforum.com/f2/2000-jeep-cherokee-no-heat-186785/

https://www.naxja.org/forum/showthread.php?t=1075366

1). Have you checked your coolant level? Is it full? Are you checking the coolant by removing the radiator cap on a COLD engine, on a LEVEL surface?
Are you able to confirm you have coolant / antifreeze circulating to & through the heater core?


2). Sounds like while you were "messing around" you flexed / bent some wiring the wrong way and caused an electrical short. Sounds like you will have to check electrical connections (continuity) on the blower motor circuit to figure out why you have power, when you shouldn't.

Where did you hear this was a common problem for burnt / melted wires on the XJ? I'd like to learn more about this common electrical wire issue.

I think that i read it on this forum somewhere, that the 97+ likes to melt wires behind heater controls

Thanks for the suggestions, but the problem is not related to the car not actual heating, because I can get warm air when moving the blend door by hand, but the actuator won't move it.