AC low pressure switch replacement

TBUCK126

MEMBER
2012 KIA SORENTO
2.4L
4 CYL
2WD
AUTOMATIC
65,000 MILES

AC on Max and blowing hot air. Compressor clutch not engaging at all. Pressure gauge on low pressure line is giving very low to no pressure reading. Want to replace low pressure switch, found the location of the switch right next to the windshield washer fluid fill. Can you confirm this is the correct AC low pressure switch and what are the steps/experience in replacing this switch?

1 Reply

STEVE W.

MECHANIC
12,963 POSTS

Welcome to 2CarPros. If you have measured low to no pressure in the system the transducer is doing what it is supposed to do and shutting off the system to prevent compressor damage because there is a lack of refrigerant. It monitors for both high and low pressures.
First thing I would do is connect a set of gauges to the system and see what both high and low pressures are. If you are seeing under 20 psi on a warm day you are very low on refrigerant. Then I would recover what in the system, most machines will weigh it, yours takes 21.1 ounces +-.5 oz. If you only have the front AC and 26.4 if you have front and rear AC. If you see a lower number you have a leak. Then pull a vacuum and see if it holds. I'm betting it won't. That means you need to find the leak. A quick way is to connect the gauges to regular shop air and use a spray bottle with water and some dish soap in it and spray all the lines and connections as well as the cores and compressor. You likely cannot get to the interior parts but check all the rest. If you see bubbles you have a leak.