What should I do about this truck's A/C?

[rationull]

We have a 1999 Suburban that only gets driven about 1500 miles a year (a tow and utility vehicle). Its A/C has never been in top shape since we had it, but it used to work at least. It seems like all of a sudden earlier this year it just stopped working at all, although it's possible it was a more gradual decline that I just didn't notice. Since it doesn't get many miles (but does get 20-40 mile round trips when it does get driven) I always tried to have the AC running whenever we drove it, but apparently that didn't help much.

Anyway, it just blows ambient temperature air, and the compressor cycles on and off more rapidly than I think it's supposed to. I can test it and give more details if needed of course.

Since my perception is that it happened "suddenly" I'm suspicious that something may have blown or been damaged, causing a serious leak. But again, that's just my perception. Does the compressor cycling (more often than normal) mean anything? Is it possible it just needs to be charged?

 

[tomcat27]

I believe it is low on its charge - since the cycling has increased. if you lost all of it, the compressor would not cycle at all.

 

[Trav]

The fact the compressor is cycling is a good sign, its not empty.
If it were a blown line or seal it wouldn't run at all as the low pressure switch would cut the power to the clutch. Try recharging it first, chances are its just a little low.

Edit: Tomcat beat me to it, posted at the same time, same answer.LOL

 

[artificialist]

Also check to see if the condenser is full of garbage and if the fan clutch is losing its grip. Either condition will cause the high pressure side to rise dramatically, causing the high pressure switch to cycle off the compressor.

That in mind I would have the refrigernat recharged first.

 

[rationull]

I will check out the condenser, but I'm pretty sure it's clear. Pretty sure the fan clutch is OK too but it's got an auxiliary electric fan for the A/C anyway.

Good to hear that it could just need a charge. Now, to buy a gauge set or take it somewhere? Hmm...

 

[mechtech2]

With R134a, more is not better.
Take it easy if you charge your own.
Or, look for specials that abound for AC service.

 

[Chris142]

The compressor on that truck is known as a belly leaker. Look around the body where the 4 parts meet for signs of oil or dirt sticking to the oil.