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  Topic Review (Newest First)
05-29-2020 02:25 PM
jtec Something is wrong of the high pressure gauge only goes to 75psi.
do you have both high and low pressure gauges?
05-29-2020 01:09 PM
RussB81 You don't want the high and low side the same. if it is 80 degrees outside you want around 40psi low and 250psi high. The high pressure switch shouldn't kick off the compressor until 400+ psi. Under 20psi the low pressure switch kicks the compressor off. Have you changed the pressure transducer? It is the part that talks to the PCM. You need a DRB-3 tool to read the transducer. Before you go that route though....

How much R134a did you put in? It might need more. Pull the plug on the low pressure switch and jumper wire the contacts. This forces the compressor to stay on. Add R134a to the low side until it reads 30+ psi. This is how the factory manual tells you to do it. This is how I do it. Also, never ever use the leak stop type R134a. Use the little regular cans without the flashy graphics and marketing claims. R134a is a standardized formulation and that stop leak goop clogs the system and makes things worse.
05-22-2020 10:13 AM
AC Compressor questions, please help!

I have installed a new ac system in my 2003 Jeep Liberty 3.7

New accumulator, new condenser, new compressor, all with correct measured amounts of PAG46, and also a new liquid line with orifice tube, and all new gaskets and o-rings on every connection.

Pulled a vacuum and checked for leaking psi, then pulled a vacuum before introducing R134a.

I put about 3 oz of pag46 into the compressor and I hand cranked it about 30 times before I added r134 or plugged in power...

What I am getting here is the same issue I started with... The compressor kicks on and off for 5 seconds at a time, over and over...

The pressure on low side goes from 40-45, compressor kicks on, takes it down to 20-25, then turns off... over and over...

Before all the part swapping, the high side was just matching the low side, but now it seems to go up to 75+ psi when compressor is on...

Anyone know if this could be the high pressure switch or something? Or a problem with the evaporator? (The only major component I didn't replace) Keep in mind the 2003 liberty doesn't have an expansion valve in the evaporator)

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