With my driver's side window regulator hanging free outside the door I noticed that the original window lift motor would bog down and stop when running in the down direction, which winds up the regulator spring. I wasn't sure if that was due to not installing the motor in the correct spot on the regulator, whether the regulator was binding (doesn't appear to be), whether the motor is designed to use the weight of the glass to help push against the regulator spring, or whether the motor itself wasn't putting out enough torque.
Fast forward to today: I individually hooked up both the old motor and a new Dorman motor to the door harness and checked the DC current (Amp) draw of both while running using a DC clamp meter. Surprisingly I got a lower current draw for the used original Toyota window lift motor than the new Dorman. After a few runs in both directions the Dorman drew 2.35 Amps and the original Toyota motor first drew 1.54 Amps and a few minutes later it pulled 2.13 Amps. Best guess why the motor drew more current after it warmed up was maybe due to the armature bearing-bushing clearances tightening up?? The Toyota motor did get a bit warmer than the Dorman at the far end of the armature "tower", but this was after a dozen runs up and down. The new Dorman sounded a tad smoother and maybe ran a bit faster.
Earlier I had sent an email to a Dorman tech rep who said a good motor will have a no-load draw of less than 5 Amps, so the used motor easily beat that assuming the same spec applies to the Toyota part?? Next I'll hook the Dorman motor up to the regulator to see how it does compared to the original motor.
Edit: before the test I had completely disassembled the Toyota motor, cleaned and relubed the armature bushings, worm gears, pinion gear shaft, lightly sanded the commutator (1000 grit), and checked the brush lengths.
Second photo shows the Dorman motor no-load running current, bottom photo is the original Toyota motor result.
Fast forward to today: I individually hooked up both the old motor and a new Dorman motor to the door harness and checked the DC current (Amp) draw of both while running using a DC clamp meter. Surprisingly I got a lower current draw for the used original Toyota window lift motor than the new Dorman. After a few runs in both directions the Dorman drew 2.35 Amps and the original Toyota motor first drew 1.54 Amps and a few minutes later it pulled 2.13 Amps. Best guess why the motor drew more current after it warmed up was maybe due to the armature bearing-bushing clearances tightening up?? The Toyota motor did get a bit warmer than the Dorman at the far end of the armature "tower", but this was after a dozen runs up and down. The new Dorman sounded a tad smoother and maybe ran a bit faster.
Earlier I had sent an email to a Dorman tech rep who said a good motor will have a no-load draw of less than 5 Amps, so the used motor easily beat that assuming the same spec applies to the Toyota part?? Next I'll hook the Dorman motor up to the regulator to see how it does compared to the original motor.
Edit: before the test I had completely disassembled the Toyota motor, cleaned and relubed the armature bushings, worm gears, pinion gear shaft, lightly sanded the commutator (1000 grit), and checked the brush lengths.
Second photo shows the Dorman motor no-load running current, bottom photo is the original Toyota motor result.
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