Webasto 66232B
 

I have recently had a Rover 75. I have found that the FHB is not working, even on cold days. Sometimes I can see that the housing is hot next to the coolant hose, but the exhaust is cold.
The model I have is the 66232B.
I recently did a test, with the engine off and with a high outside temperature and when connecting pin 3 to positive, it made a turbine sound that I suppose is the pump, I don't know if it's diesel or coolant. This lasts a little over 1 minute and turns off.
At the power supply connector, 12.76 volts arrive.
The exterior and the exhaust are cold, but I do notice that it sucks in air.
What else can I check?
If necessary, to disassemble the Webasto, could you do a bypass to be able to drive the car without it?

Yes. Just connect the input and output hoses together. If you do not have a FBH then it is just a continuous hose which you have to cut to fit the heater.

if you drive the car in summer and all is fine, will it not still be fine in the winter?
Does it make any difference if the webasto water pump is not running, could that cause over heating?

have you a multi meter to check the glow plug resistance?

If you want a working FBH pm Deivlish or Trebor, members here and ask them about checking the PCB as these are known to fail.

Can you hear the webasto fuel pump by the near side rear wheel intermittently coming on and off? I am assuming you are left hand drive?

macafee2