Help!

I have searched and i find a bit of information pointing to both for my issue.

Here is my issue, Blower Motor works 95% of the time. Some times it doesn't turn on at all, but a good ol fashioned smack, gets her going everytime on the bottom of the motor.

Do you think this is a resistor issue or motor. The speed variations does sometime show up as abnormal which leads me to the resistor but that can also mean a "loose" winding as well.

Thoughts?

Thanks guys!

Trey

 

Well, a blower resistor just resists current based on the selector position. When it goes bad, it cannot resist anymore and causes the fan to be on High at all times.
'If you have all fan speeds, it is not your resistor.
You could have a bad connection or a bad blower motor.

 

Thanks.

Isn't the resistor a Potted one? Therefore regulating the current/voltage going to the motor and that's where you get your speed selection?

Motors aren't that bad in cost these days, maybe I will just replace them both....

 

Sounds like you've got a connection problem or a winding problem on the blower motor... just replace the blower motor and see if that solves the problem.

I think they are sealed units so you won't be able to access the windings to see what's going on in there...

 

Yes, but when resistors go bad, they are an open circuit. Open circuit means no resistance and allows the blower motor to run with as much current as it wants. This means High speed only.
If there's any variation in speed controllable at the dash control unit, the resistor should be good.

I would follow Izero's advice. Just replace the blower motor and see if that solves the problem. No sense in throwing another $50-60 at it for no reason. Maybe the resistors are less/more. i dont know.

 

Thanks guys. You are right about the sealed unit. Already took it apart as far as I could and cleaned it.

Replacement is on its way.

 

most likely its the brushes for the motor.

as the brush wares down the spring puts less pressure on brush.. loosing contact...
but most motors are not repairable. and brushes are getting harder to find.

 

Why don't you test them with a meter? At least in my career field nobody wants to be labeled "the parts changer".

 

That's the problem, its intermittent. I've removed it and bench tested it a couple times. Works just fine once removed. Harness is good as well as all other wiring.

My multimeter showed the resistance through the motor within tolerances.

 

My '07 Ram 1500 SLT QC does the same thing occasionally. I replaced the blower resistor & it still does it. But I can smack the bottom of the motor & it'll start back up at proper speed. I'm guessing the brushes are going bad.