Temperature control is by left and right hot engine coolant radiators, after the one AC evaporator, each with its outlet thermometer (that you can see just inside the left and right center grilles). MAX shuts all the flappers except those that blow in your face, sets blower speed to maximum, and thermostat to 60°F. 1. p4ddy.b. 117 posts · Joined 2017. #9 · Feb 25, 2017. Not dying to hyjack the thread but my tests maybe showing the same issue. I've just tested the power to the relay when the switch is pressed and when off I have 12v to 30,85,86 and 0v at 87 on the relay. When its on I have 12v at 85,86,87 but 0v at 30. The heater valve should not have any effect on the cooling fan. When the coolant fan is not working properly, it will shut the AC system down to prevent the engine from running hot. If you have INPA or DIS, there is a test to check the operation of the coolant fan. There are 4 stages the fan operates on, depending on the temp. With fan on high and grounded to the door hinge, I am seeing 12 volts on the green and yellow with greeen strip. The small blue wire is at 8 volts. The brown and tan wires are both <1. As I am rotating the FSR in my hand to check the last wire, the fan suddenly starts blowing. As I "jiggle" the connection, the fan starts going on and off. mattmar1. 7608 posts · Joined 2014. #4 · Oct 29, 2020. there are 5 "flaps" under the dash controlling air flow thru the ac/heater box, all controlled by stepper motors. if one of these faults, it will usually show up as an IKHA code. as youre getting full defrost heat, but not getting full heat output from the dash vents, id check the just out of curiosity, where is the heater control valve located on the 2006 e90 bmw 325i? i took off the cabin filter and frame but I could not find it. if this vehicle has a heater control valve, they do a good job of hiding it. The panel can be removed by first removing the cup holders, and pushing the panel out. The fan can then be cleaned. If your heater blower is running when the ignition is off, the final stage unit is bad. There is a new style FSR available, that has about 3X the number of spikes as the old style. Remove plug from fan and run 12v live from battery to equivalent live on fan . Run earth from fan earth to an earth point in engine bay. It should run. If it does then it's likely to be the fan switch. This will be found on most cars either in radiator or one of its feed pipes. Vay Tiền Nhanh Chỉ Cần Cmnd.

bmw e90 heater fan not working