Right, my fan relay 4080 thread has run out of bit of steam, so I thought a new one with a more interesting (juvenile?) title may help

I have now established that the fan circuit actually runs the high speed fan but not the low speed (my MultiESCUscan software wouldn't actually run either but I think that's a fault with the software or connection as the whole actuators page wouldn't run any of the tests ?).

So, that suggests to me that the actual relay itself (in the box by the battery) must be OK as it runs one of the fan speeds, but poses the following questions:

Are there actually two relay boxes (one to run each speed)?
Could it be the switch itself on the fan ?
Or a resister (again, is there one for each fan)?
Or is there ano control box in line to check?

Most importantly, I guess, does anyone know if the Multi's set up is like some BMs where to correct a faulty switch, resistor at the 'fan' end of the set up, you have to buy the whole bally lot inc the housing, fan motor, the lot (big £s obviously)?

As usual, all contributions gratefully received...

ePER by the way, isn't tremendously helpful; it shows just what looks like the whole assembly as "10409" whatever that is, and then as "M7" for my model.

So I guess my Q is, has anyone been down this path before and have any insights to share?

Thanks.

I think there are resistors to control the speeds.
When I had a problem it turned out to be chafed wiring down by the radiator.
I think the resistor (s) are down at the fan end.