A/C Question for the F-350
 

Ok, so pulling the boat the other day and after 20 minutes the a/c cuts out. Hot air. So I turn it off, drive down the road and a few (10) minutes later try it again. It works for 5 and cuts off. Comes back on after 10-20.

So on an 80 degree day it seems to work fine. On a 100 degree day, it works for 15 minutes and then cuts out.

I dont know a lot about a/c, but I have gauges and heres what I found out.

It was already hot and kicked out. I hooked the gauges and had 120 on each side. The a/c was on (inside) but the compressor was not. I sprayed water on the condensor, it dropped the pressures to 100 and the compressor came on. Work for a minute or two, until the high side started climbing from 275 to about 450. At 450 it cut out. It leveled back down to 120, so I thought maybe it has too much in it. I took some out (down to 100) and it worked. Drove it for 20 minutes, cut out again and pressures were at 120 again. Drained more out and now the compressor kicked on and off (low). I added some back in and its the same situation.

When it first kicks on, the low side is about 40ish and the high side is 250-275ish.

Help. I dont like pulling the boat with no a/c on 100 degree days :drink::eek:

what year is the truck and what size engine,

2004 F350 with a 6.0 diesel

Does the Low side start falling cignificantly as it runs for a few minutes?

That was what mine did on my jeep. You start the Car and run the AC at full capacity. After a couple seconds my low side would drop and the compressor would kick off. Filled it up with a 10 dollar kit from Advance and I was good to go.

On an F-350 related note, though mine was a 7.3 and this doesn't seem like your problem at all, my AC was intermittent, and come to find out the Wiring Harnes on the low pressure side was not making a good connection and would intermittently kick the compressor off-line. Pulled the harness, bent the prongs slightly, sprayed them with some contact cleaner and knock on wood haven't had a problem since.

is it elec temp control or manuel

there is a switch on the manifold line that is known to have the wires rub on the belt and can cause a interm. problem, but your pressure is too high when it is running, check to make sure the fan fan clutch is working correctly and if so there is a restriction, we have put on alot of dryers due to the bags busrting internally.

Classic symptoms of a slightly low charge. I would have evacuated and recharged first.

Jason,
I don't have any a/c help for you but was wondering what boat you got back into? Still got the plane?

More PSD knowledge here than you could imagine.
Check this board out;
http://www.thedieselstop.com/forums/f5/

it is not under charged ! the head hight side pressure WAY to high...should be 274-300 range, the 120 is normal when compressor not running and pressures equalize. something is causing that high head pressure, and the safety swith is cutting off the compressor before something goes boom...may be a restriction in the line, clogged condensor, hard to tell without seeing it...Rob