[Vwdiesel] 1980 Rabbit Diesel Pickup parts

[Mullaney, Steven]

I'm looking for parts for the above vehicle:   1.  the coolant
temperature sensor (which apparently determines when the engine is
warmed up enough to shut off the glow plugs, and 2.  the heater control
box (this is how it's been described to me; the heat and blower is on
all the time).  
 
This is my daughter's car and unfamiliar to me, so the descriptions
above are from an auto shop that has it at the moment and can't locate
parts.   Any help appreciated, including info if the above descriptions
don't make any sense to someone who knows the vehicle.  This is a pretty
expensive outfit, and it would be nice to know if they know what they're
talking about before I pick the truck up!
 
Thanks,
 
 
Steven Mullaney
Department of English Language
  and Literature
University of Michigan