Need help A/C low side pressure keeps rising
Thread Starter
Burning Brakes
Joined: Jul 2004
Posts: 1,087
Likes: 10
From: Hernando MS
Need help A/C low side pressure keeps rising
Replaced a/c compressor, dryer orifice tube and flushed out the lines before re-assembling and proper amount of pag oil used. Vacuumed out the system for 45 min and vacuum holds. Charged the system with 24 oz of Freon resulting in 37lbs on low side. System cooled perfectly for 2 days then the low side pressure rises to 120 after 2 more days of non use. The compressor will not engage even if I bleed the low side down to 35. If I pull a vacuum and recharge the system the car will work just fine till the low side rises again after sitting for a few days. This has happened twice. Checked the orifice tube and its installed correctly. I am not sure why this is happening.
On rethinking this maybe the issue is why is the compressor failing to engage? I was thinking it wasn't engaging because the pressure was too high. The low pressure is possibly at 120 because the system is at rest due to the compressor not engaging. The fuses are good. Why has the system worked after recharging
?
update: turned out to be the relay for the A/C in the fuse box
On rethinking this maybe the issue is why is the compressor failing to engage? I was thinking it wasn't engaging because the pressure was too high. The low pressure is possibly at 120 because the system is at rest due to the compressor not engaging. The fuses are good. Why has the system worked after recharging
?
update: turned out to be the relay for the A/C in the fuse box
Last edited by flash of red; Jul 31, 2013 at 06:51 PM.
Thread Starter
Burning Brakes
Joined: Jul 2004
Posts: 1,087
Likes: 10
From: Hernando MS
I checked the fuse and it was found to be good . Knowing the other culprit could be the relay. I just pulled the horn relay which is identical in design switched them out and the compressor kicked in and all is well 
Nice cold air again. Relays can be tricky since you cant just look at them to see if they are bad like you can a fuse.
Since I was taking it for granted the relay was good from the beginning; I created a lot of unneccessary trouble for myself.
Nice cold air again. Relays can be tricky since you cant just look at them to see if they are bad like you can a fuse.Since I was taking it for granted the relay was good from the beginning; I created a lot of unneccessary trouble for myself.
Last edited by flash of red; Aug 1, 2013 at 01:14 PM.
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 795
From: Longview Texas
I checked the fuse and it was found to be good . Knowing the other culprit could be the relay. I just pulled the horn relay which is identical in design switched them out and the compressor kicked in and all is well Nice cold air again. Relays can be tricky since you cant just look at them to see if they are bad like you can a fuse.
Since I was taking it for granted the relay was good from the beginning; I created a lot of unneccessary trouble for myself.
Nice cold air again. Relays can be tricky since you cant just look at them to see if they are bad like you can a fuse.Since I was taking it for granted the relay was good from the beginning; I created a lot of unneccessary trouble for myself.
