Air Conditioning Problem.

geezer · Post by **geezer** » Mon Jul 14, 2008 7:48 am

My a/c blows hot air, I thought it just needed a charge so I put the gauge on the low side connector and it level looks good. Any ideas on what to check next?

Thanks.

Post by **HenryJ** » Mon Jul 14, 2008 7:50 am

Low pressure switch.

geezer · Post by **geezer** » Mon Jul 14, 2008 8:08 am

where is that and how would I check that?

Post by **HenryJ** » Mon Jul 14, 2008 9:55 am

If your pressure is up, check it for continuity. It is on the filter dryer.
Unplug the connector and jumper it. If the clutch engages, that tells you the clutch is working.
If the switch does not complete the circuit is does not have enough pressure to close , or the switch is bad.

geezer · Post by **geezer** » Mon Jul 14, 2008 10:03 am

the compressor does kick in but it shuts off quick

Post by **HenryJ** » Mon Jul 14, 2008 10:21 am

You need to check it with a set of gauges. It is likely that you do not have sufficient charge and when the compressor kicks in it draws the pressure on the low side down far enough to shut down.

You really need to monitor both the high and low pressures to judge the system condition.

What was your pressure with the compressor engaged?

geezer · Post by **geezer** » Mon Jul 14, 2008 10:49 am

it's in the light blus section of one of those ez-gauges somewhere between 25 & 45 psi. How do you measure the high side pressure?

Post by **HenryJ** » Mon Jul 14, 2008 12:39 pm

You need a manifold gauge set. With the compressor clutch engaged it should maintain somewhere around 30 lbs. (temp dependent) on the low side. Installing a jumper to bypass the low side switch may be needed to keep it running long enough to diagnose.

Another possibility is moisture in the system over pressurizing the system and the high side switch kicking it out. That is where you need to measure the high side.

An AC manifold set is needed to properly diagnose. The low side gauge you have will not be enough for the high pressure side where it could exceed 350 psi.