Air Con Pump question

[Aprisa]

Right, finally on the road and came to work in the kit this morning. Everything is going pretty well except that whilst in traffic I suddenly got a large amount of screeching and billows of smoke out of the back of the car.

I assumed it was the alternator belt and have just removed same, had to take off the Air-con belt to do this and it seems this is the culprit, its a new belt and was pretty tight but its obviously been slipping and has burnt a little.

Question:- I have not yet had the system charged (next job) and I thought that unless I depressed the Air-con switch it would freewheel without harm ( I realise the system has no lube until charged), can I be doing any harm in letting it rotate with no gas or has the pulley been slightly siezing and causing belt slip?

I know nothing about air-con systems at all, just bolted it all together!

Any ideas?

Nick

[Mr2Mike]

The pulley is (usualy) connected to the compressor via a magnetic clutch. This clutch is only engaged when you turn the air-con on, and there is also a pressure switch that ensures the system cannot be engaged if the refridgerant pressure is too low.

The pulley obviously spins on a bearing when the clutch is not engaged, it's possible this has seized.

[Aprisa]

Thanks
That's as I thought, may be that the belt was too slack and it was slipping even without being engaged?

I'll run it with the belt off until I get it checked out. Can't miss taking it to Silverstone on Sat!

Nick