The wife came home in our 97 Wrangler this evening and mentioned the AC fan only worked in the hi position, all the others positions the fan didn't work.

I just changed the evaporator coil and hoping the fan motor isn't bad and I'd have to take the evaporator/heater box out again to change a fan motor!

Got any guesses? please tell me the switch is often the case
and the fan motors are bullet proof.

Doug

Usually it is neither the switch nor the motor.. Behind (I think) the glove department is the device that sends the correct amount of voltage to the motor from the switch.. THAT is the culpret...most times.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

Thanks jim, I'll take a look. I am guessing it's a module plugged into the fuse block and something will be marked fan speed control?

It is a resistor that puts out different voltages for each fan speed. The failure usually goes to hi-speed fan only.
I have never replaced one but I have read about them a LOT.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

I used to replace alot of the blower resistors on TJ's. Just be sure to check the electrical connector on it too, as they sometimes have overheated and melted terminals. You can get a replacement connector if it's bad.

I opened the glove box and found the FAN relay, it only operates when I turn the switch to the HI position. Looking at the useless Haynes manual it gives a brief schematic and shows the resistors for speed control, but dosent show where they are.

Anyone got a clue where they are?

Doug I have read that it is BEHIND the glove box. So I'm guessing the box must be removed to get at it. I've not had the problem so I've not looked for it..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

It's low on the heater box, behind the glove box area, if I remember right! There may or may not be a small cover over it, too.

Here's a link to a picture of it:

http://c2c.activant.com/ctoc/index.jsp?ID=bEz1sGyk_BU50LyZ_CUdGM2RDUF86ZTEKUnIf

Thanks all,

I did find the module, it's below the dash on the heater/AC box, just to the right of the light mounted under the dash.

You have to remove the cover under the box, the cover protects the vacuum cylinder that opens and closes a vent down there. The resistor unit is mounted thru the housing with 2 screws. It is easily found, it has a connector with a bunch of wires. I spent sometime on the internet researching the unit. What typically goes bad in them is a 'thermal fuse' not to be confused with a current fuse that blows when you draw too many amps. This one blows when things get too hot. Mine had a bit of trash stuck inside that probably reduced the air flow causing the 'thermal fuse' to blow.

The bad part is, Auto Zone and Advanced want about $50 for the part. So I am looking on line for a 'Cost Effective' solution.

Check with the dealer, they might have it cheaper.

If you have a pick-your-part type yard in your area, one from a late model XJ cherokee would be the same thing and should be easy to find.