Help me if you can. My heater fan on my TJ stopped working. I have already replaced the fuse behind the dash compartment, replaced the resister, and was prepared to replace the fan motor but before I did I jumped the old one out with a hot wire and ground and it worked perfectly. What else could it be ????? Is there a second fuse that's not labeled? Help.
The actual switch where you adjust the fan speed also when u take that out wiggle wires plugged into the switch box could be a loose connections on my moms 01 the plug with 3 wires on the right side as you pull it out was melted changed the connectors works like a champ
What yr is it? The system changed between '98 &'99. 3 dials or dial & 2 sliders?
When jumping to the motor jump just the hot side then just the ground side (key on). If it works with just the hot wire then you are losing the power. If it works with just the ground wire then you know you are losing the ground.
If it has the 3 dials ('99+) then the ground path is from the motor to the resistor, to the speed switch, then to the mode switch then to ground. Since no speeds are working it is not likely either the resistor or the speed switch. That pretty much leaves the mode switch or the wiring & most of the time it is the 3 wire connector to the mode switch which is melted or burned (as stated above).
I've taken it out and put it back in several times including the last time I replaced it with a new one. The plug is not melted and seemed to be in good shape. I'm really scratching my head and am just before taking it to a dealership, and I really can't afford that.
Well start with testing with the jumper one at a time to determine if you are losing ground or power. Almost every time it is getting power to the motor but losing ground. When that happens on all speeds the one place in common is the mode switch which grounds the motor in all positions except "off". That is the only time the fan should be off. The speed switch & the resistor use different internal circuits for various speed settings so both are highly unlikely to bad on all speeds at the same time. The resistor is actually bypassed on high so that is ruled out if you have no high speed. If the 3 wire connector looks good, unplug it & jump between the 2 heavier wires (bottom 2, I think). With the key on try the speed switch in each position. If all now work you need a new mode switch.