w140 heater/ac blower

[92300SE]

I just got a w140,early model,1992,with a dead blower motor.I grounded the blower directly and it works,full speed,so,I assume regulator is faulty.The one on the car is a Behr,I dont know if that was the factory model,before I spend 100$+ for another one,is there anything else worth checking?ACC seems working,I can hear switching vents when I push the buttons also it will turn the AC compressor on if set on defrost...