Drane MPGA10084 motor trouble

[Tsuriman]

Motor started making noise yesterday and today stopped spinning. It is making a lot of noise, whining trying to get started.  I cleaned a bunch of the lint and grime off the motor and it blew hard for a while.  But the next time the furnace kicked on it didn't blow again.  Making noise so I shut it down.

 

I know the obvious thing is that this very old unit and should be replaced but does this sound like a motor issue?

 

Let me know the next step. 

[Tsuriman]

Ducane, not Drane.  Sorry

[RegUS_PatOff]

with power removed,

give the Motor Shaft a spin with your fingers.

Does is turn quietly, smoothly ?

[ACtechGUY]

Motor or capacitor or both.  Motors do wear out.  get a new motor and new capacitor to match the new motor. 

@RegUS_PatOff

Sometimes a motor will spin freely with no sign of bearing damage and still be bad. FYI 

[RegUS_PatOff]

he mentioned Motor "making noise" ...

would seem to be Motor Bearings

[Tsuriman]

motor did spin freely.  Then at one point a bit of a grind.  but went away.  

I have video.  and got it running again.  Will post shortly.

I got it running set with "Fan On" setting.  The heat shoudl turn on but it is not.  Is there a reset?  I have a feeling it got really hot.  

[ACtechGUY]

A motor with a weak / failed capacitor will cause motor noise.  Also there is the case of capacitor wiring  inside the motor going open( due to bad capactior) and you can replace the capacitor and still have the same problem. 

 

Tsuriman - older furnaces had a thermal fuse located  inbetween the flue and burners. That may have blown to excess heat. This  stops low voltage from getting to the gas valve.  

[ACtechGUY]

due to the age of your furnace , before you invest ant money in a motor ......

 

You should thoroughly check the heat exchanger for cracks /  rust holes . 

Pull the blower assembly out and put a bright light in the burner section. When looking into the hole where the blower blows into , you should see no light. if you see any light , the heat exchanger is failed and funace must go.