The blower motor does not come on.

Prior to blower motor not working completely, it appeared like the motor would occasionally stop working for a second, and then continue working...weeks later, the blower stopped working on L-M1-M2... almost immediately after this the blower worked only on H, intermittently, for 2 days, then not at all.

1. Both the 50Amp (under the hood) and the 25Amp (left side of dash) fuses are good. (continuity test – ok), but I still swapped them for other similarly rated fuses in the respective panels.
2. The blower motor resistor was replaced. The harness looks in good condition.
3. The old blower motor is good (12V test – ok)... and the new blower motor works no better than the old one when installed... both purple and black leads look okay. There is a voltage at the purple lead on L-M1-M2, and none at OFF (as I'd expect) and H. The black lead is grounded (continuity test to metal strut at behind glove box – ok).

Can someone explain what this means and what might be my next steps to solve this problem of the blower motor not working?

 

Sounds like it is the switch since that is about all that is left.Mine did the same almost,it quit working on 1 and 2 but would run on 3 and four.After a while it just quit. So i started replacing from the motor back and ended up being the switch on the cluster.

 

Thanks mel902, I appreciate your input. I had not given much consideration to a faulty blower motor switch.

 

Mel902, you called it. Installed a new blower motor switch, and all is working well! Thanks