Hopefully this weill help someone.
Living in New England heat is essential....a few weeks ago my heater fan blower stopped working. I was able to wiggle the wires leading to the resistor module under the glove box to get it to work. I dealt with it for some time. I go to the parts store to order a new module......$20 for a module without Auto Climate control......$170 WITH Climate control (and I have AUTO climate control). Pretty pricey.
After further inspection, it looks as if someone else had already hacked in a new pigtail to the module. I take the module out to find a loose piece jiggling inside. The plastic cover is removable but in order to get the connector plug out I needed to cut all the wires leading to it due to the fact that the plug was melted to the housing (which was why I couldn't get it out).
Long story short, I found a diode came un-soldered and the ground wire was arching....I was able to solder the diode back in, hard wire new wires to where the plug connector was and it fixed the problem.
Nice to have heat again.....and I saved myself $170!!!
Most probably would have replaced the whole module, but a little investigating and taking a shot at fixing it paid off.

 

I had a Dodge Caravan with the same problem, ie, melted plug. When I went to the parts counter, the guy asked me if I needed the plug also. I asked if this was a common problem and was told yes. Must be a Mopar thing!

As far as I know GM still uses Bakelite for their connector, Chrysler uses high temp nylon.