I replaced my blower motor, blower motor resistor, and still my blower doesn't work. It sucks cause it's 32 degrees here and going without heat in the car is killing me.

I used a test light and I'm not getting any power to the positive wire on the blower motor connector so this leads me to believe that the only other things it could be would be the actual fan speed switch or the relay itself.

Does anyone know the part number for the relay? I figure that's a cheap and easy thing to replace before I assume it's the fan speed switch.

 

The fan speed switch won't keep power from being present at the blower motor.
With the ignition on you should have 12V at one side of the blower motor connector with it unplugged. Plug it in and with the heater/ac off you will have 12V on both sides. The switch provides several paths to ground through the resistor to create different speeds.
There will be two fuses and a relay involved in getting power to the blower motor. The relay should be a standard Bosch type and you can substitute one of the others (AC clutch) for testing.
Info for a 97 or newer XJ.
Good luck.

 

Thanks for the help! I checked the blower motor fuse under the hood and it's good. I also checked the 'climate control' fuse in the cabin and it's good as well.

Is the AC Clutch relay under the hood or behind the glovebox with the blower motor relay?

 

Not sure what your rig is. If you have found the blower motor relay then just sub it out with any other that is the same. The AC clutch relay was just an example.
You should have 12V on pin 30 and if you jump it to pin 87 to get power to the blower motor.
Pins 85 and 86 are the low side (control side) of the relay. One will get power and the other will get ground. When the relay engages it connects pin 30 to pin 87. You can test the low side with a test light easy enough.

 

Gotcha! I'll test it tomorrow and see what I find. It's a 98 Cherokee Sport 2 Door FYI.

 

BTW, something I might point out that is odd... The guy I purchased it from (who is an idiot!) had the positive connection on the blower motor itself running directly to the positive terminal on the batter with an inline fuse.

He then had the ground connection on the blower motor running from the blower motor to the blower motor harness with a wire and a male connector for one end and a female connector for the other.

This was causing the blower motor to work, and oddly enough the fan speed switch was working as well in all different positions. I didn't want this ghetto rigging so I took all the wires off, plugged the blower motor back in with the factory harness, and now nothing works.

So, from what I gather this idiot was trying to bypass the original problem by hooking the blower motor straight to the battery, right?

Well, I got a new blower motor resistor for cheap and sure enough that didn't fix it. So now I'm basically down to just the relay. If it's not that I have no idea what else it could be, literally. All I know is the guy before me must have had it stop working on him so instead of troubleshooting it and fixing it the right way he just took the easy (and ghetto) route.

I took a test light today and tested the positive (green) cable coming from the harness that plugs into the blower motor. The car was turned on and I tested the wire with the fan at all 4 speeds. Sure enough the test light didn't light up which basically tells me I'm not getting power to the blower motor.

Here's a photo of the blower motor wiring when I bought the car.

 

Sounds like the previous owner cobbed it up pretty good. I'd guess it will all center around the relay. One of the 4 elements will be missing.

 

I think it's probably because the guy before me was some 17 year old kid whose parents bought him the car. I'm fixing all of the things he did wrong on it. The only reason I bought it over another Cherokee was because it was a 2 door!

 

Okay so I have power on pin 86 of the relay when the ignition is on. However there is NO power at all to pin 30. What could that mean?

 

Also, what I find even more odd is that when I use the test light on the plug that connects to the climate control ***** it doesn't have ANY power to ANY of the wires while the ignition is in the on position. When I turn on the headlights however ONE of the wires gets power to it, but when you turn off the headlight switch the power goes off. So, that makes me think that that one power wire is just for the lightning on the climate control *****, but shouldn't there be a constant power going to that plug regardless?

 

Disregard the circuit that powers up with the headlamps. That is just an illumination circuit.
12V on pin 86 with ignition on is a good thing. You should have constant ground on pin 85.
It would seem that no power to pin 30 is your issue. Pin 30 is fused by a 40A fuse in the PDC. Fix that and you may be in business.

 

I just tested the fuse in the PDC and sure enough it is getting power to it as the test light DOES come on. This leaves me scratching my head yet again. Power to the fuse but no power to pin 30 on the relay.

Thanks by the way, you've been a tremendous help!

 

did you have the key on when you tested the fuse connections

 

Nope, just did try it with the key on and the fuse is indeed getting power to it. Yet still no power to pin 30 on the relay.

 

what year?