Dismounted my GC and found out that the AC pump is not PWM, it's just ON/OFF, the electromagnetic clutch type.
When I start the engine the AC pump is turned on immediately, and it stays on even if it's cold and I ask for heating in the cabin.
On the HVAC panel there is no wire that seems to operate the AC pump, if I turn off the HVAC panel, the AC pump is turned off after 3 seconds.
I think the HVAC panel send somebody else the AC pump request via CAN bus.
I disconnected the AC pump connector and the bad smell is gone
I am happy
now I can breathe while driving
The AC pump connector is hard to reach and operate, and I don't like to have it exposed to dirt and oxidation, so I would need to know if there is a relay or fuse I can easily remove to stop the AC pump.