Dr pepper
Member
My heater blower initially worked slower than normal then stopped altogether.
First I tested the wiring and heater resistor by t pinning a headlight bulb across the blower motor connector, the lamp came on and changed brightness with the speed control, so the wiring was ok.
I pulled the motor, put 12v across it, nothing, so I pulled it apart, the inside of the motor where the brushes are was full of black crud, upon close inspection there is a filter just above the blower, looks like it contains carbon, this had disintegrated and the cooling air guide for the motor had carried this carbon or black stuff and dumped it all over the brush gear and commutator, some of the segments on the com where fully covered and therefore insulated, so the motor would only start if it stopped on a good segment, and when it ran it went slow with lots of vibration. Running the motor of 12v with the headlight bulb in series to slow it down and polishing the com with 400 grit emery cleaned up the com, then dosing the whole thing in wd40 then switch cleaner appers to have got it working again.
Certainly cheaper than 60 quid for a newun.
First I tested the wiring and heater resistor by t pinning a headlight bulb across the blower motor connector, the lamp came on and changed brightness with the speed control, so the wiring was ok.
I pulled the motor, put 12v across it, nothing, so I pulled it apart, the inside of the motor where the brushes are was full of black crud, upon close inspection there is a filter just above the blower, looks like it contains carbon, this had disintegrated and the cooling air guide for the motor had carried this carbon or black stuff and dumped it all over the brush gear and commutator, some of the segments on the com where fully covered and therefore insulated, so the motor would only start if it stopped on a good segment, and when it ran it went slow with lots of vibration. Running the motor of 12v with the headlight bulb in series to slow it down and polishing the com with 400 grit emery cleaned up the com, then dosing the whole thing in wd40 then switch cleaner appers to have got it working again.
Certainly cheaper than 60 quid for a newun.
Last edited:
