MrCarbon

so i bought this 95 jeep cherokee SE with a non working heater. I took out the climate control and found a melted pigtail that goes to the fan speed switch. I found that the fan speed switch was broken so i replaced the switch and i cut the melted pigtail and just hand wired the switch myself instead of buying a new pigtail. So then the heater only worked on the highest speed so then i replaced the heater resistor. After installing the heater resistor the heater worked fine on all speeds for about ten minutes and then a burning smell came to me and it stopped working again. So again it only worked on the highest speed..(burnt heater resistor). After some research, I went and bought a new heater blower motor and another new resistor. AFter installation, i carefully watched the resistor and after about 1 min its starts smoking. I have checked for continuity on the wires from the switch to the resistor and they all check out fine. I have checked for power at the wires on the resistor and power exists. Obviouisly there is to much current going through those resistors which causes them to burn. Im purdy good at electronics and Ive been looking at the wiring diagram and I just cant figure it out and im running out of options. this is really frustrating please help??

MrCarbon

o yeah and also, no blown fuses, is there like a relay i can check or somethin?

useitorlooseit

alot of times things will heat up because of increased resistance due to a bad connection check your plug ends on all connections to make sure there not loose and they are tight!

Trailorr

I just rigged my fan to a "on-off" switch because I was dealing with the same issues from the previous owner.

MrCarbon

I will check .....thanks

MrCarbon

I might have to go this route

Trailorr

MrCarbon, this is what I did.

I ran my ground wire and ran it through the firewall right where wires run near the pedal assembly. Same goes for my positive wire off the battery. Their is a little coin pouch area right before the e-brake handle is and that's where I drilled a hole for my "on/off" switch. It's temporary because I broke the piece in of that entire console piece and I need to buy a new one and I have a new idea for a mount area for my switch.

I ran the negative wire to the switch as best I could through the back end of the center console - done. I then ran the positive wire through the vent system followed by pulling it through the two screws that hold console in. Here is where I ran the infuse fuse wire. I then ran the wire back down the other side of the console to the switch. Done.

I know I skipped a few steps of how I wired the blower up but it's common sense and I can't remember how I did that . But here is the pictures of what I did.

motohed

You should also check your ground for the chassis , and try running a temperary ground from the battery . check your amperage draw with the ground and with out . my guess is you are drawing to much amperage due to a bad ground .

Trailorr

Of course, I only have fan speed "high" or "off" but if it gets to hot, I just crack my window or turn the fan off. Right now it's not bad because it's winter but come spring time, hopefully I will have this entire issue fixed. It's been bugging me. But it works.

useitorlooseit

ya sounds like a good i idea

MrCarbon

Well in that case (simple on/off wired fan), i dont even need to do anything cuz the high speed works just fine. The way this motor is wired is that it has different speeds. different speeds is caused by different voltages. different voltages are caused by different resistors. thats where the heater resistor comes in which all it is is four resistors in series and each resistor causes a different speed. when u switch your fan on high all its doing is bypassing all the resistors and going straight to your fan giving it its full power. I guess i could do what u did but i would just like to make it work how it should since i already put money into. it seems that there is to much current for the lower speed resistors which burns them up but not to much current for the motor itself. but then there is no blown fuse?aaaaaaahhhhhh im going nuts just thinkn bout it....im sure this is an easy fix but a really tricky

Trailorr

I've done what you described earlier, get it working on all fan speeds and just smoke and stopped working. Hence why I went the route I did. If you find a solution that makes this last longer then 10 minutes, PM lol.

MrCarbon

haha ok