bjl95mustang

I just took a trip to florida. While driving with the a/c on low after about 1-2 hours the a/c will barley blow on any speed. If I cycle the compressor off the a/c will slowley defrost and start blowing fine again. And if it's sitting while the a/c off with the blower on water will start to pour out the drain.

I checked the a/c charge and it's fine. I tried searching and all I found was there couls be a sensor, but that was with the auto a/c. I have the regular a/c.

Where do I start?

And I also saw the drain issue and i'm going to fix that too.

picaflor

it may be clogged.

diamonbird

The water is from the iceing over......usually if it's iceing over it's low on Freon.

ShaunnP

Low charge or plugged coils

bjl95mustang

I only had the little low pressure gauge for filling but I got these for LOW side pressure.

I added a can yesterday during my trip cause it was icing up.

72F outside right now.

Idle - 40 Psi
1500 - 33 Psi
2000 - 30 Psi

I did notice that the compressor never cycled off during this readings. I was out there for 30 min.

JimWills

I'm not Mr. A/C but there is a pressure sensor that tells the compressor to cycle on and off depending on pressure on the high side. You can usually hear it go on and off at idle. the other possibility is there is also a filter in front of the orifice these used to clog up on older Fords which were notorious for the A/C hosed breaking down from the inside. Best bet, take it to a pro.

jayson_waltz

You gotta get real gauges to test both sides. If its freezing up its probably a little low on freon. And btw you should never just add a can without having good test gauges hooked up to make sure you don't overcharge by much. If you dont have that capability or knowledge on ow to do that, just take it somewhere and have them do it for you. Its not an expensive thing to do.

bjl95mustang

I was out of town and only had the little crappy gauge. My dad has my good set of gauges so I'm going to go get those from him.

I found the ford manual on pressures and diag.

as of now it looks like a bad pressure switch. But I need the gauges to confirm.

sfdude

With 134a, pressures are of little use. A slight undercharge of 3 or 4 ounces can cause a freeze up. You need your system evacuated, a vacuum pulled, and recharged by someone that has a good machine with an accurate scale. Being in the business, we see this quite often when customers take to a shop that still tries to do it "old school".

There are other causes, but a slight low charge is the most likely culprit.

rollingthunder

That must have to do with capacity.........


I charge systems in the field all the time using 134 a... the only reason I even have a scale is for billing, I just charge off my gauges, and vent temp.. If I'm sitting at 20/200 and have a vent temp below 50....



However, I'm working on systems that hold 5-8 lbs of 134a.... Not sure how much these trucks hold, 2-3?