Blower fan not working
 

Hi all
My blower fan now does not work at all, before it would sometimes not come on but would eventually come on, now nothing at all. So I pulled the cover from under the glove box, ran a negative to the fan motor and it ran great. I then checked voltage at the plug and would get 14. Volts. What and how do I test further , is it a bad porcupine resistor or ccu unit.
Thanks

Sounds like typical symptoms of a bad blower motor resistor. Sometimes they can last years working intermittently before they fail all together. I'm sure there's a way to test it if you know which wires are + input and output.

What is the year and model?

-Matt

Sorry my car is a w126 300sdl 1986

More info needed. Model, year, tried pushing low-high-autospeed buttons. Later models have a blower speed relay box which works w underhood resistors box.

If a negative made it run wouldn't that indicate a bad ground?

Clean it up with compressed air and lube it.