2000 Cherokee, I recently replace the blower motor resistor pack after it went bad. Looked like a piece of a paper towel was wedged in among the coils, shorting things out, I'm sure.I've replaced the blower motor relay, thinking it was stuck open, but that was not the issue. I'm getting power at the relay with the key off. I can turn the blower motor off only by turning the heat/ ac/ defrost switch to off. Admittedly, I'm terrible with electrical issues, but I really don't have a clue here and have no idea how to track this down. Has anyone dealt with this before? I didn't see anything in a search.
Thanks, in advance.

 

Sounds like your blower motor relay is stuck shut or something is TELLING the relay to stay shut. Here's the wiring diagram. With the key off, blower motor running, pull fuse 25. If the blower motor stops, it's a signal issue. If it still runs with that fuse pulled, pull the blower motor relay. If it stops, see if you can temporarily swap the blower motor relay with another random relay. If it doesn't come back on, you have a bad blower motor relay.

 

I've already swapped the relay, same thing. I've pulled #25 previously and that stopped it. I've also swapped out the HVAC control panel with another. I don't know what else to look for.

 

check the relay behind the glove box. think its a green plug last time i looked but dont quote me and see if any wires are melted.

 

The really weird part is that if I remove the relay, and then replace it with the key "off", the blower motor does not run. If I turn on the key, it will run, and continue to run with the key off.

 

Pull the fuse panel from behind the passenger kick panel. It commonly gets wet and corrodes, then causes all kinds of weird stuff.

You can clean it with a small wire brush and some electrical contact cleaner.

Sometimes it works out, sometimes it doesn't. Worth a shot though:

https://www.cherokeeforum.com/f2/int...-block-163403/

 

Thanks, I'll take a look. My last post has me puzzled the most, because it would seem like the blower motor would power on instantly the relay is connected. I can unplug the relay while the fan is running, then plug it back in and it is not. There is some sort of switching action going on, somewhere other than the blower motor relay.

 

Does it stop if you just tap on the relay. Might just be a sticking relay.

 

Checked out the fuse panel, no corrosion. I guess I'm going to have to find a local electrical wizard auto mechanic to take a look. No, it's not the relay, IT'S BEEN REPLACED.

 

It seems I've fixed the issue. I'm guessing the resistor pack going bad/shorting out led to the hardwired GPS system getting zapped and it looks like it was the culprit. After removing it, I've had no problems with it beeping at me after the key was removed or the fan running. So weird.

 

im currently having the same issue, what did you replace to fix it?

 

I removed the hardwired GPS. It was spliced into one of the wires from the ignition switch. I've not had any issues since then. Do all of your blower motor speeds work?