I know this isn't a bonneville message board but I know the V6 camaro and the bonnevilles should be a bit similar. My dad has a 90 bonneville (209k and ticking) and the AC would run then just turn off, after a while it would kick in again. It's not a performance problem with the AC, when it's on, it's cold. Its like a switch being flipped on and off. My dad got the AC cycling switch replaced, but it's still acting up.

Any ideas what else it might be?

 

either low pressure from low freon or high head pressure from the fans not coming on

 

Is there a way to check the freon? Ill check the fans ASAP

 

Not a good way unless you have a pressure gauge. He should have 2 pressure switchs. a low and a high. which was replaced? if you can not find the other one then it;s probably on the back of the compressor. this is your high side pressure switch. the only way to change that is to have the system ecaed and pull it out.


If you can not get a hold of a good manifold gauge set spend the 20-30 bucks to take it to a shop for an AC check. If they try to sell you something other then freon then they might be taking you for a ride. It's hard to say without being there.

Now. since it;s a 90 it's probably an R12 system. so even if it is low you can NOT fill it yourself. they can top it off with a product called freeze 12. but first see whats going on. when the compressor kicks on if the high side doesn't head for 350 and the low side doesn;t imediately start sucking down to 10 or less then you might just have a pressure switch bad.

if the pressure on the high side hit's around 300 and then kicks off the high side switch is cuting power cause it;s either overcharged or the fans are not coming on or there is debris on the condensor.

if the low side sucks down past 20 then either it's low on freon or there is a blockeg in the system