ChickenLover

This last weekend I took a trip to eastern Nevada. I headed out there at night and my AC worked just fine (as it always has). The trip back was done during the day (100+ degrees), the runner was extremely loaded (3 people and a lot of heavy crap with no space to spare). The drive is mountainous and at high elevation (5-9k).

On the trip back the AC just stopped working. I don't even think the magnetic clutch was engaging. Just blowin' hot air. This would last for about an hour or so. Then it would start working again for about an hour then stop again and so on. According to my engine temp guage, everything was fine.

A mechanic friend of mine told me that AC units have some way of shutting themselves off when the psi gets too high inside (a self protection method). Can anyone confirm this? And if so, does this sound plausible in my situation?
My AC has worked just fine ever since returing home and letting her rest. Any thoughts would be greatly appreciated.

dragon564

I can confirm that the runner have a pressure switch on them, I do not know if it is for a high press or a low press, but it is the connector is that is on the can looking thing up front.

ChickenLover

Well after reading up on it in my fsm, it looks like it was probably a refrigerant pressure problem. There are a few different safety switches (dual pressure switch, triple pressure switch and thermistor) that will cut power to the A/C when the refrigerant pressure is too high or low. Or when the evaporator output temp is too low (to prevent freeze up). So I'm guessing that the load, heat, and high elevation threw the pressure off.

TPI

funny how you mention that topic, my did the same thing yesterday, it was kinda hot, it stopped working but then i stopped using it for about an hour or less tried it again, and it was blowing cold air again.......wierd

94x4

Try having your systems completely vacuumed down and then recharged.

waskillywabbit

iTrader: (-1)

That will solve your issue...typical sign of a system in need of a recharge/reset.

Flamedx4

Many times this happens when the system is marginally overcharged. The pressures would get too high in the most severe conditions and it shuts off for a while. Releasing a little refrigerant would be the fix. To know if this is what is happening, you really need to have gauges connected. Trial and error does work, but if wrong you have to put some refreigerant back in. If the pressure is a bit low, it would usually not stop working, it would just not get as cold but run longer cycles.