Johnly

Have the dash of the Cherokee opened up trying to figure out where it the issue is.
The fuse is good and getting 12V on both sides of it.
No voltage present at the resistors and all measure good.
No voltage measured at the speed control connector, and no signs of thermal stress.
The blower motor was starting to sound like a bearing was going out. After the blower quit functioning,
I kept the fan switches in the "On" and occasionally it would start running, but the next time is was non-functional.
Is there any way the blower motor going bad would explain the voltage measurements that I'm seeing?

Thanks!
John

cruiser54

Shoulda replaced the blower motor right off the bat.

Probably burned up the brown wire at the ignition switch and the resistor pack by waiting like this guy did.

gat

A worn fan will pull more current and cause more heat than engineered to run thru the wiring. You will have to find a wiring diagram for your year and submodel, then trace backwards to find the, presumably, open wiring.

cruiser54

That ^^ fan is a bit worn, eh?

gat

Ive never had one of my Cherokees lose a blower motor (1992 & 1988 x 2), but my Wrangler (2001) **** the fan and took the cable to the resistor with it. I was thinking that Cherokee fans were invincible.

Johnly

Thank you for the info. I replaced the ignition switch a while back, so I know how to get into that area.
The other electrical items that toggle with the ignition switch seem to be working, so I didn't think to look there.
The vacuum controlled air selector has an Off position that also can shut the fan off. I was also thinking of looking in that direction as well.
John

cruiser54

If radio and turn signals don't work also, the brown wire is burned.

Jeepwalker

Remove the blower motor and see if it spins or is tight. My fan has started making noise a while back. When I recently re-did my heater core I removed the rubber hose and got in there with some Mobil-1 oil ...a few drops specifically placed with a piece of wire at the bottom of the motor (back bearing) so a little oil would 'run down' to the bearing. Worked it a little. Let is sit overnight so oil would soak into the back bearing. Then removed the blower cage and did the same for the front bearing. I used a hair dryer to soften the plastic a little where it fastens to the shaft so I could pull it off w/o damaging it. So far it's running smooth as new. .

The motors use oil impregnated bushings, but after many years that oil can become cooked and basically old and no-good. A few drops allowed to soak in can sometimes get ya years more use. At least for me, since I mainly use my Jeep in the winter.

Otherwise buy a replacement blower, but make sure when you do, the rubber tube hole is in the right location. I'd buy locally than over the internet, so you can reject it if it's wrong. The other guys gave you good advice on potential wiring problems.