Help with Heater motorised valves

[Dutchone]

I have got two problems with the heater control system (96 Serp) which relate to the servo motors and/or valves for the fresh air/recirculation valve and temperature shut off. I would like some advice on what to do next in the way of checking or changing the motors and/or valves.
Rather than put a long and probably boring diatribe on here it may be simpler to ask if a kindly person with experience of getting to/checking or changing these valves and motors could give me a pm through my profile.

Many thanks to anyone who is brave enough to enter my mine-field.

Cheers, Paul