Heater Fan, wont turn off

my n reg 2.0i sx series 2 decided it would turn the heater fan on full this after noon,and it wont turn off or down, its the panel with three dials ,the ctr one is for direction of air and the outside ones are for temprature of each side of the car, and sliders under neath for fan speed and recirculation and fresh air, has anyone had this problem or knows what could cause it, could you let me know if theres an easy fix, or is it a weekend job,,,,,cheers ....terry

Could be one of the regulator transistors on the motor has gone short circuit, or, less likely that there is a fault in the control unit. If you look on the motor I think that there are two plugs, one with two thick wires, red and black, that bring the main supply, and another plug with thinner wires that comes from the control unit, if you pull this plug out and it stops, its the control unit, if it doesn't, the fault is on the motor. You can change the transistors, much cheaper than a new motor, or alternativly get a secondhand one from a scrapyard.

Peter.N.

sorted my heater out, i replaced the motor/fan unit with one from my S1 donor car, its suprising how many bits are interchangable between S1 andS2 cars......terry

Hi,

I guess that this is a question for Peter N.
What type are the two transistors? are they the same or different? mine on the fan I am trying to repair are so corroded that the printing on the cap is unreadable. If they are different then I need to know which is which as both look to be TO3 cans.

Thanks in anticipation

XMexc

dont know what tranies are on my S1 but they have got to be 12v and the plug fitted and it worked?????. i never looked at the transistors, ,,,terry