ShaneJackson

I have an AC that will damage the belt tensioner if I go above 1700 RPM's. The system is not cycling, the compressor stays on all the time. I've changed the low pressure cycling switch with no change. Has anyone had this problem. The AC blows cold air and had this problem going on for about a year. I just keep the RPM's down, but is a pain starting from stop. I've read that it could be the compressor, but it just doesn't make since. I believe it has something to do with the cycling. I was thinking about the high pressure switch, but that shouldn't be used for normal operation.

Rednucleus

I assume if you turn the ac off the belt is fine and the compressor is not running?

tech2

cycling off or not....the system should be able to run up to wide open throttle without damaging the a/c tensioner.


from the information you provided... if the tensioner is ok at any speed with the a/c system off, how can it be anything other than the compressor?


Maybe have someone check the a/c high and low side pressures for something unusual. Remove the a/c belt and spin the tensioner pulley and a/c compressor(the compressor clutch and the compressor).

ShaneJackson

I know the compressor is causing the jerking on the tensioner, but is something else causing the compressor to react. i.e. clogged orifice, overcharged. I was checking pressure and trying to compare to online videos, but the videos do not show everything like what pressures you would read with AC off, low pressure side readings when the AC is first started. My low pressure starts around 80 and slowly PSI drops to 30 PSI (about 3 to 4 minutes) I expect it to start cycling but it doesn't (I suspect clogged orifice) and the high side was reading around 200 PSI. I want to try and find out before investing in a compressor then find out that isn't the problem. I do not take my vehicles to mechanics because I've been lied to too many times. I once had a Blazer and had my AC checked out and they said I needed to replace the whole system and gave me a list. I went through the list and saw low pressure switch, so I changed that and it worked fine. So I do not use mechanics. I do all my work, just haven't worked on an AC to understand for sure what my pressures should be just a chart I found for a running AC. If I change the orifice and it isn't the problem then I will have to change the compressor and spend the money on refilling again, so I'm trying to find somebody the may have seen this before.

cleveland63b

I'm having a hard time figuring out what your actual symptoms are that you're trying to fix? The compressor is always engaged?

cj1

Does compressor clutch engage/disengage normally when a/c turned on/off?

If so check the PSI rating on the low pressure cycling switch and compare to gauge reading. The low 30 psi and high 200 psi seem close but maybe 30 isn't low enough for the cycling switch to open.

Air in system/overcharge/compressor are suspects if low side can't be brought down. Maybe release a bit of refrig to see if pressure drops.
If not then pull vacuum see if it holds.

tech2

thanks for insulting technicians everywhere shanejackson.
depending on the build, dual, single...the system may not be a cycling clutch system. Some systems vary the displacement of the compressor and its runs all the time the a/c is on.
the pressures are normal. check the tensioner, is it weak?

Rednucleus

Cracks me up how often people come here for free advise but first insult most of you guys that are trying to help. Guess he never heard the "One bad apple" thing

ShaneJackson

The tensioner has been changed twice. As for the on bad apple, that was just one example. Every time I go to a mechanic it is the same thing. I'm sure there are honest mechanics, but I never seem to find them.

cleveland63b

theres my favorite part...most mechanics/technicians have nothing to do with how you're treated or what you're told. Unless you go to ma and pa shops where the guy doing the work also does the paperwork and office work then you likely aren't hearing what they would say or do. Countless times I've ran into customers outside of the shop and what they were told isn't even close to what I wanted them to be told by the service writer/manager.