PeterG
Senior Member
I have a 1990 International 4900 dump truck. The cab heat blower motor would not work in the middle speed, just low and high. Then the fan starting making noise. I cleaned the whole system out of Mice debris. Then the blower only worked on high, and then starting not working but going on only once in awhile. I thought it was a bad connection. I have replaced, the fan motor, the resistor, the resistor harness, and the fan switch. It now works great on low and high! Can't get it to run at the middle speed. On the new resistor harness, there are 4 wires. On the truck, only three wires. Does this have anything to do with the middle speed. Not a big deal, I can live with low and high speed for defrost or cab heat, but considering I have replaced everything, what am I missing? Any International 4900 experts out there?