I'm eating blower motor resistors right now. Last week I changed by blower motor resistor because speeds 1-3 weren't working. The new Motorcraft replacement worked great at first, but this morning I smelled the magic smoke (that burning electronics smell) again and sure enough the speed I was using -- #1 -- stopped working. That was about an hour's use. I took a closer look at the electrical connector:



Time to start troubleshooting.

Some quick searches show that the HVAC switch and the blower fan seem to be the most likely culprits. I pulled out the blower fan, this is what I saw:








I know the best way to tell is to measure the current draw while the fan's spinning. Does anyone have any idea how much it should draw if I jumper it to the battery?

I also did a spin test, but I have no clue how much its supposed to turn. I flicked it with my fingers and got about 1/2 - 3/4 turn out of it. It doesn't spin totally freely, but I don't know if its supposed to

 

No idea, but cool write up

 

I have no previous experience with these particular motors either. But I would certainly expect it to spin much more freely than that.

 

Ones in other cars I have dealt with, the fan would spin pretty freely and coast several turns before stopping. I would try a new fan.

 

There is no question, that motor is shot. There should be *no* resistance to the spinning effort, and that cage will spin lots and lots of times before stopping if the motor's ok. The increased effort to spin the cage on it is why the resistors are blowing, more current needed to move the cage.

New motor. Pronto. And of course, another resistor.

 

Cool thanks man. Yeah I do kinda want all the speeds working. I ordered the fan and resistor this morning

It's not coming in till mid-next week so I put the old one back in for the time being. I guess I've got the Lazarus fan. All of a sudden all the speeds are working again. But the parts are ordered and #1 is pretty faint

 

Got the fan installed the other day, the new one spins so much more free and the air is a lot faster now too. Man, my old one was shot. The Lazarus resistor is still installed and working fine

 

Glad to hear, as it sounds fixed!