so when i bought my truck 2 weeks ago, they said the sucked down the a/c and refilled, i didnt think they had a reason to lie except that they are a car dealership, but the a/c was cold, and i was happy. well 2 weeks later, it's hot, the a/c compressor keeps kicking on and off, so i figured i had a leak, i went and got the gauges, hooked up to the low pressure side was 90ish psi, which i know is too much...now i couldnt get the compressor running long enough, so maybe that reading is inaccurate....
would you say that the place probably just put a bottle of the recharge in it without checking, and now it's over filled, i have a bad sensor....or i dont have enough refrigerant, and my 90psi reading is inaccurate cause the compressor wasnt constantly spinning..

 

90psi would be a good STATIC pressure.. meaning with the compressor NOT running.
And if your compressor is cycling on/off quickly maybe that is what you are seeing.

What is your high side reading?
In order to have overfilled it to have an operating pressure of 90 psi your high side would have to be something like 600... and I don't think that would be possible.

Sounds to me like there is a leak, and your compressor is cycling too fast for your guage set to keep up.

 

I too think there is a leak.
Do you have a one of those leak detectors? You could just get the UV kit from parts store and some UV leak detector to put in the system to locate the leak, also while at the store get a pack of o-rings for 134 if that's what's in it.
Probly just one of the o-rings leaking.

 

i assumed the pressure would fluctuate, up or down i wasnt sure, if the compressor is running constantly, but what i dont understand is, if there is a leak, why am i seeing that kinda pressure, if that's a good static pressure, then how can anything else be bad..and why would the compressor cylce like that

also thanks for the quick replies...it's hot here.
i was hoping to find a decent forum for these trucks, looks like i have.

 

I was wondering that as I typed...about having good static pres. but why your clutch cycle.

I guess I would just check the whole system.
Find your low pressure cutout switch by-pass it..see what happens to your pressures - especially watch the high side.
If your condensor is plugged - or not getting cool air from dirt/grass/bugs/whatever your high side will peg and trip the high pressure cutout switch.

 

i bypassed the switch yesterday, just to see if the compressor would stay on and it did...i didnt have the gauge hooked up at the time, i gotta go grab my tools and try again
the condensor is clean as can be...
im not sure if i have a gauge fitting for the high side, im using the crappy gauge that came with a recharge kit

 

Could be the switch maybe, they can go bad and make it kit in and out.
You need a guage set, 2 gauges for high and low pressure. The 2 have different fittings.
Youll wanna watch the high and low side. With the compressor kicked in all the time the pressure needs to be around 40 on the low side. I'm unsure about the high side I think it's 300 but I don't want to lie to you.

Might want to check to see that your clutch fan is working properly, if it doesn't move enuff air it will do the same as debris in the condinsor. It needs air passing through to keep it cool.

I don't know much about this but I watch my dad/my boss do it all the time at the shop.................................

 

2001 Ram Service Manual (other years should be similar):
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any shot at you getting me the procedure for testing the low pressure switch...
im assuming this is my problem, as the gauge didnt say it was low, and when i bypass it, the compressor runs,,

do you know if removing the l/p switch will cause and refridgerant to discharge