carolinaXJ

So my blower fan will not come on at all. Ive replaced the control switch panel, blower resistor, checked all fuses and I jumped the fan straight to the battery and it works like a champ, just will not work through the interior controls, anything else that I could check??

jeepesh

Take a multimeter and make sure you have power to the heat position selector harness. On my 1995, this was a yellow/tan and black wire if I recall (there should be schematics online). I had bent one of the pins for this harness working blind and found it while checking here for power. Straightened the pin, reconnected the harness, now it works great.

If you have power there, then check at the speed selector switch, then at the resistor and finally at the blower motor. This should at least give you an idea where the break is.

carolinaXJ

Checked power at all locations, finally got to the blower motor plug and removed it. It test 13.95 volts so I guess the safe bet would be a bad blower fan, but it doesnt make any sense why it works when its straight wired but not from the interior controls. Anyways gonna get a blower fan tomorrow, thanks for the advice!!

aa7kn

well I had the same exact problem, mine was working great one day and the next no blower....everything checked good. I unplugged the blower connector and checked voltage at the female connector on the harness, 12 volts on high, plugged it back into the blower and the blower wouldn't work...I cut off the connector and wired the blower straight to the harness and it has been working great ever since....it was a bad connector for sure. I couldn't even ohm across it when it was hooked together. so might try that.

crazydays

Im going to bring this topic back to the top because I am having the same exact issue.

I never saw him post an update. Anybody else help me out before I go spend $$$.

Thank You!!

Pelican

This is in a '97 and '00? Fan works when you hot wire it to a power source but not otherwise?


In your situation I'm not sure where I would start spending $$$. Probably take my meter and start checking components and connectors.

crazydays

This is in the 1997. Yes blower motor works when jumped directly to the battery.

I have 12 volts at the connector that plugs into the blower motor as well as fuses, etc.

I'm stumped!

DFlintstone

"Back Probe" to check power and ground with it plugged in? Then work back.

Maybe start by putting a good ground right to battery NEG, then go back up the POS till you find where it's not getting through.

Btw, sometimes an old motor will start using a nutty amount of current. I had a Tempo fan that worked great! Just it would blow a 40 amp fuse. Yours might be stressing some connection. (which will be warm/hot, if that's the case)

crazydays

Thanks. I will give that a try tomorrow to see what I come up with

steelybill

I'm new to the Jeep world, and don't want to muddy this up, but there must be a switch in the heat/AC selector lever, since the blower doesn't run in "off" on the lever, at least on mine....or, is the blower speed so slow that it's not detectable to the ear ??

Reason I bring this up, is that if there is a switch in there, it hasn't been mentioned in blower problems....

carolinaXJ

Yea sorry I completely forgot to update this. Check to make sure your fan isnt jammed up inside of the dash. My problem ended up being that the blower fan was jammed up inside the dash, i ended up having to remove the entire dash. Once I did that I saw that the previous owner had also removed the dash for some reason, however when he put it back together he put the air box in wrong. So the fan part of the blower was actually touching something and was not able to spin, so it was just jammed up. I could remove the fan and wire it straight to the battery and it would work, but when I reinstalled it would always go in wrong because the dash was not put back together correctly.

carolinaXJ

I dont think there is a switch. The entire system including the selector *** runs off of vaccum. Someone please correct me if I am wrong

CCKen

There is a blower speed switch. It's the rotaty switch.

'97 was the first model year for the climate control panel with rotary switches.

The fan speed switch is electical, the Mode Selector is half electrical, half vacuum, and the Temperature Control is cable operated to the Blend-Air Door.

Also, this is the first model year that the blower speed is controlled through its ground circuit, as opposed to controlling power to the blower.

Refer to the blower diagram below. It's for model years '99-'01 but may include the '98. The '97 is the same but different (LOL). I don't think the '97 has connector C209.

If you check for power control at the blower connector know that if you get 12 volts to the blower, the fusing is okay, the blower relay is okay, and the blower relay control is okay. To test use your voltmeter to probe at the blower connector power pin (+ probe) to the ground pin (- probe) and have someone turn the ignition switch to ON/RUN, then turn the blower speed switch through all the speed settings. You should see the voltage vary at each setting. If you don't see varying voltages, or any voltage, the ground control circuit is open.

If you want to see if the blower fan is stuck, you can roll down the glove box (two rubber stoppers) and look straight in at the Recirc Air Door, and through the grid to the blower fan. You can use a long screwdriver to reach in and prod the blower to see if it's stuck.

crazydays

Thanks CarolinaXJ, it is plugged in and removed from the dash with no luck.

CCKen - Thank you. Heading out to use this soon. I don't think the voltage changed yesterday when I was checking. So you think bad ground somewhere??

CCKen

That's to be determined.

If you use the system gound control circuit as the 'ground' while check voltage you'll find out if there's a bad ground. Using engine or chassis ground when probing the blower + connector won't do in this case.