Blower motor fan speed selection switch not working

[Jerry Bransford]

The resistor pack only provides the three lower fan speeds so when those don't work but the highest speed does, the resistor pack has blown. BUT (!!!) what actually causes the resistor pack to blow is a bad fan motor whose windings have started shorting together. The winding wire is bare copper that is coated with shellac and when the shellac starts breaking down the windings start shorting together. The bottom line is you need to replace your fan motor too or it'll just eventually blow the new resistor pack too. Avoid store brands too.

 

[blthomas]

As a update, I started stripping the loom back. I wanted o test for voltage at the firewall where its easy to work. Stripped the sheathing, went to put battery back in, I had forgotten about the fat sector wire under the PDC.

I poked it, and it literally popped open. Repaired that section, installed battery, and now have voltage on the same wire at the fire wall. Need to assemble the column, see if I finally have hazards.