This is my first visit, and thank you for all of the good information. My 2001Voyager also has a bad resistor pack. Thanks to your posts, I found resistor pack quickly behind the glove box. You guys did all the hard work for me. I greatly appreciate it.
Now, the long version.....
OK, I'll admit it, I'm a tightwad. I dug a little deeper wanting to know what went bad with my resistor pack. Before using your posts and a schematic I found online, I was thinking about replacing the blower fan switch.
With the resistor pack out, I was surprised to see the resistor pack had four resistors that were large coils of wire. Something peculiar caught my eye, there was one more component inside that didn't appear to be a resistor (omitted from the schematic). I remove the large heat shield from the resistor pack to expose the internal components. I ran some quick continuity checks with my ohmmeter. All of the resistors checked out fine. I check from the spade lugs on the pack and also at the end of the resistor leads. There appeared to be some minor corrosion internally where the resistors are attached internally.
Centered between the four resistors was an interesting component that looked like a diode. Running a continuity check on that component I discovered it was 'OPEN'. I removed this component I got out my magnifying glass. The markings on this component are as follows.
Microtemp
KKKAJE
G4A15
128C ( 128 Celcius, 262 Fahrenheit....that's hot)
This component is a thermal fuse made by a company call Thermodisc.
http://www.thermodisc.com/productdet...p?ProductID=34
Here is a data sheet link.
http://www.thermodisc.com/loadMedia....&ReturnPage=14
I was not able to find this readily available. So, I went to Digi-Key and I'm 'trying' a similar component. Another name for this component is a TCO, or Thermal Cut Out.
This part costs me 98 cents, so I ordered three. UPS shipping is ~$6.61.
( Please, I'm not an expert, just cheap ). Another name for this component is a TCO, or Thermal Cut Out.
Digikey part number: 317-1133-ND
Description: THERMAL CUTOUT 128C 10A AXIAL
Unit Price: 0.98000
Troubleshooting: I've learned a few more things about the resistor pack. The schematic I worked from was a bit misleading, it appeared that the four resistors were in parallel, this is not correct. Why does the fan only work on HIGH when the resistor pack goes bad? The thermal fuse is the only path for current entering the pack. Why does your fan work on HIGH only? The pack is wired to bypass the thermal fuse and resistor pack completely.
How does it work when the pack is good? Let's start on the HIGH setting. The resistor pack is bypassed and the blower gets 12V. When you switch it to the next lower setting, one resistor is added to the path of electricity going to the blower, slowing it down. Each time you select the next lower setting, an additional resistor is added to the circuit. At the lowest setting, all four resistors are in the circuit ( the lowest setting ).
My guess is the lowest fan setting will generate the most heat ( all four resistors are in the circuit ) Why did the thermal fuse blow? I will have start with a just component failure. Time will tell.
If you'd like a picture of the resistor pack with the thermal fuse, let me know. I'll email it to you.