the problem started when my original left window lift motor quit (97 F150). connected the motor to the battery and it was definitely dead. put in a new motor and it worked the rest of the day. Next day didn't work. pulled it out and tested with no load. worked fine put it back in and worked all evening and next morning. didn't work in the afternoon but worked again next morning. there is no measureable resistance through the switch and voltage to the switch is 12.2. all tracks and regulator mechanisim have been lubed and window slides up and down fine.

I know these motor have a thermal limiter which stops the motor at full up and full down. Since the motor works okay when it is 45 degrees but not at 70 is it possible that the thermal limiter in the motor is bad? also tried another motor and it quit after lowering the window about 2 inches. it also worked fine with no load. No one including Ford and NAPA makes a new motor are these rebuilts motors the problem? anyone had a similar experience?

Thanks

 

the problem was bad rebuilt window motors from NAPA.In one weeks time I ended up going throgh 7 motors until I found a good one.

2 fron NAPA that were bad out of the box

1 Dorman from PEP Boys that has the left and right part numbers mixed up

1 Dorman from Autozone that sounded like the gear had broken teeth ( these motors are junk)

1 rebuilt from Ford that was the right side motor when I needed the left. My fault for not checking first.

1 rebuilt from Ford that sounded like a cat in heat

1 good rebuilt from Ford

Ford does not carry a new motor for the 97's and neither does NAPA. The only good new motors are Cardone Select if you can find a jobber that carries them.

Next time I will go directly to Ford