[LeRoux Strydom]

lol, maybe you screwed up more than the airbag unit when you did the radio swap...

Seriously, the ccu is right next to the radio. I would unplug everything back there, maybe clean out the little fan at the rear (which is known to cause problems when all the dust gums it up), refit and try again. That UK site also has good info on how to test the servos. It not difficult to do, trouble comes when you have to replace the leaky a/c evaporator. Ask me how I know...