Re: elec. fan runs continuous
You can see if it is modulated with a rms meter. a meter with RMS or root mean square relationship is an AC meter. Looking at the signal in AC and DC range will give an indication of the signal.
IF it is DC your dc reading will some value and the AC reading will be close to zero, if it is PW modulated, the AC reading will be signficant though the reading will be largely meaningless as it is a square wave pulse, but your note the AC nature. The meter can not be a harbor freight meter as its AC scale will read DC in one direction as its a half wave rectifier and if reversed on DC it will read nothing.
Sorry for the tech talk mumbo Jumbo. If you have a fluke meter the motor voltage will be metered in both DC and AC. Bottom line, was the relay or module replaced??
On day two of car ownership I checked my module and found it was digitally controlled by the computer, and I did no more with it. Plannned on controlling the speed but digital and me are not on speaking terms. WW