My A/C functions properly, but there is whining sound whenever my A/C's on. The whine will be instantly gone when I switch off the A/C. What is likely to be the problem?
not always as my many years in the trade has taught me lol but you are right the tensioner normally is noisy all the time but sometimes it only happens when more load is appliedAs a rule, if the tensioner bearings have gone, the noise will be there constantly, whether the aircon's on or off.
For a noise to come with the activation of the aircon, you're looking at either a loose belt (belt squeal), a slipping aircon clutch (not usually a whine) or a stuffed compressor. (again not usually a whine)
You'll have to do further investigations.
Check that the aux. fan hasn't been hot wired to come on with the aircon clutch.
More of a roar than a whine though.