THANK YOU for all the replies ! .

I'm not sure what the ' PBU ' (? Push Button Unit ?) is , I have a rebuilt one but the temp. wheel has always been very stiff on it .

I'll have to go looking for my FSM and see if I can find the testing chapter .

At the moment I'm driving my '84 Euro Spec. 300TD , it has Kilma II and heat so we're good to go but I really want my Coupe to have heat too .

As long as we're here , what is the current suggested Coolant choice ? .

I *think* it was Zerex a few years back , at the moment I'm using Honda typ pre mix coolant as it's O.K. on the alloy parts .

But , I also do a change and flush every two years in January so if i should swap to one of those yellow coolants , I will .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better