Looking for some advice on my 96’ 4.0. Awhile back I was getting lots of noise from my blower motor but still had all my controls. After I received it back after loaning it to a buddy I noticed the blower didn’t work on any setting. I just replaced the old blower and confirmed it was in fact bad, Plugged in new blower motor and I got nothing. Tested new blower motor to constant battery power and it fired up. Checked voltage at connector and on high I have 12 volts but the motor will not turn on.

I don’t have continuity between all terminals on my resistor which makes me believe it may need to be replaced but if I understand it correctly, the resistor is bypassed while on the high setting (full battery voltage).

Thanks,

 

The resistor module itself is not bypassed. But the current will not be passed through any combination of the resistors. You may need to have the fan on highest and in AC MAX mode to achieve the highest fan speed (full current). Did you try that combo already?


12 volts at the fan connector but fan not turning? That is interesting. I believe the connector should show 12v no matter what fan setting is selected. But the amperage will change at different speeds. You should probably start by inspecting the fan resistor.


On a 96, the ignition switch, the fan speed selector, and the fan resistor can all be implicated. Because if a fan motor starts pulling too many amps as it is failing, it can begin to melt any of those components I mentioned. The ignition switch is particularly weak, because the wiring is pretty small for the amount of amps the fan can pull on high setting, and it gets no ventilation/cooling to keep the temps down inside the steering column shroud.


97 and above models don't run the fan amperage through the ignition switch. So this is something 96 and below owners need to be quite aware of. Can save a lot of trouble if you occasionally inspect the ignition switch connector and make sure everything is ok in there. And switching your fan speed one notch lower when the cabin has cooled makes HUGE difference on the amperage and temperature of those wires/connector at the ignition switch.