Blower Motor

[klippencott]

I just experienced a repair I wanted to share. My 2004 blower motor would only work on high. I first thought something was wrong with the blower motor. I removed it, hooked up power to it in the shop and it worked fine. I opened my CD full of Sprinter diagrams and found that the fan has a resistor control block in front of speeds 1-3 on the motor. Speed 4 is a direct 12 volt power to the fan. After finding the resistor block just to the right of blower motor I unhooked it, pulled it out (5 minute job). After looking at the schematic of the resistor block I started testing it. All the terminal to resistor connections ohmed out correctly except one. On the bottom of the resistor block is a thermal fuse, it had no continunity. I took my magnifing glass and found it had a thermal breakdown of 216 degres C. I went to Radio Shack and bought one that was 10 degrees higher. I clipped out the old fuse. I cleaned the metal by sanding and scrapping to the copper. I tinned the old area with solder. This next step is very important, I used a couple of small copper alligator clips attached to the leads next to the new fuse to heat sink and protect it from heat, then I tinned the leads. With the alligator clips still in place I moved the part into position and soldered it. I rechecked continunity for the new fuse and it was fine. I put the resisitor block back in the van and plugged the wires in. I went inside and turn it on. Everything worked great. I cost me less than 5 dollars to fix it.

[mendonsy]

Good information!! A lot of owners have had this problem or resistor failures. Most just replace the resistor pack. Others jumper out the thermal fuse.