Find the little wire/sensor on the thermostat on the engine and then ground the wire, see if that lets the blower come on. Sometimes this sensor fails and prevents the blower from coming on properly. Its intended function is to keep the blower off till the coolant is warmer, but if it goes bad in the open position then it will never allow the blower to power up. Hopefully this helps.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)