DIS/progman; how to test aux fan and rear blower fan?

[Riba]

The problems:
1. Auxiliary fan is not turning on, causing A/C not to work when stopped. It was working last time I used A/C (few months back).
2. Rear blower is not switching on. I checked the read ventilation grille and controls I discovered that the rotating knob was not engaging the fan switch. Easy fix it thought, however even when manually activating the switch the rear blower is dead.

Before digging in and replacing both, I would like to test them. From what I gather it is possible to manually turn each one of them on using progman and/or DIS? I have both, but after fiddling for half an hour I could not figure out how to do it.

Anyone willing to guide me like I am 5?

Thanks!