Noise From Blower Motor Resistor

[glcaines]

I have been experiencing an annoying noise while driving my M151A2. I thought it must be either a universal joint or a wheel bearing, but I eliminated both. The noise was similar to someone dragging their fingernails down a chalk board only much louder and higher pitched. It was actually ear-piercing and definitely coming from the left front. Guess what was causing the noise? It was the resistor for the blower motor on the heater. The mounting pin on one end was loose and was making the scraping noise. When I say loud, I really mean loud! The noise was caused by the internal mechanical scraping due to the vibrations from the vehicle. I couldn't believe the noise was coming from the resistor, but when I jammed a piece of wood inside the end of the resistor, it killed the noise. I have now ordered an NOS resistor to replace it. Even after I knew the resistor was causing the noise, I had a hard time believing it.

[glcaines]

Eureka! No more noise from the blower motor resistor. I received a new resistor from AJP and installed it. The mounting pins on the new resistor were solidly fixed and no more noise. Anyone that experiences a high-pitched noise seemingly coming from the left front, don't assume it is a wheel bearing or a universal joint. Check out the resistor first. It was amazing to me how much high-pitched noise that resistor could generate. All is quiet now. I attached a photo showing the old and new resistors. On the old resistor you can see where the mounting pins are missing because they fell out.

Resistor, Blower Motor.jpg

[rickf]

Thats one for the books! I have heard electronics squeal but never sound like bad bearings.