A/C Fan Motor for 'Chrysler B' Dealer System
Well it was closer to 9000, sorry. The method I used to measure was the same for both motors, and pretty crude. I cinched down a zip tie on the flat of the shaft and trimmed off most of it but left a tail. I put 12v on the motor and used a recording app torecord the sound of a credit card hitting the tail of the zip tie as the motor spun. Each tick would be one revolution. I loaded the recording on to my sound editing program and counted 10 spikes in the recording and how long it took to make those 10 spikes. The motor did 10 revolutions (spikes) in .066 seconds. 10 revolutions divided by .066 seconds gives 151.5 revs per second....x 60 seconds per minute gives 9091 revs per minute.
