I have a Electric Furnace, Last night it quit blowing, The element would come on and get hot but no blower, I turned it off and went to work,  Came home today and took it aprt, checked voltage on the blower plug, I have it in three places, 125 volts each wire, Im guessing it is a multi speed blower, Well I checked the capacitor it has voltage across it, I had another spare blower motor and went and plugged it in, it wont work either,



Now theres a small 5 wire plug next to the blower plug, If I unplug it my spare  blower will come on and run, its ony a three wire as to my old one is a five wire, Im assuming my spare is only a single speed  blower, ok I put the old blower back in and unplug that small plug and the low side of my old blower will run



What is that small plug for, thermostat?

You are not checking it properly it seems.

I'm not sure how you are checking voltage.  But, usually an electric furnace is 240v or maybe 208v.  so check the rating on the furnace.  If its 240v then I doubt that the motor is 125v.

You need to figure out which is the common wire and which wires are for the different speeds.  Then once you got that, figure out which speed your on.  then put your probes on the common and the wire that should be energized and you should have 208/240v.  If you are sure that you have all the proper voltages, then it is probably the relay or circuit board or whatever sequences the blower on.

As far as checking the capacitor you have to check the micro farad rating on the side of it and then check the actual micro farad reading from the capacitor.  YOu need to pull atleast one of wires off to do this.

Be careful, motors don't like to be hooked up wrong.

should say on the motor what its voltage is.

Hope that helps, its the best I can do without looking at it myself.

Its not an ecm motor is it?

If you could take a picture it might help.


edit- don't check any voltages to ground only check to wires actually going to the motor.