Re: Mysterious knocking noise!
Originally Posted by
Judd
->
AC systems are belt driven, it could be just the belt that's slipping like a fan-belt does from time to time?
Hi Judd,
The compressor is driven by the main belt via a pulley - yes.
However, when the a/c is not in use, the pulley free-wheels.
When the a/c is switched on, the pulley is pulled in via an electronic clutch to turn the compressor. If the compressor is seized, as soon as the clutch pulls in, the pulley will stop, making the belt squeal, if that makes sense?