a/c freezing up

[Cj Ford]

Well I have a problem with the a/c on our 97 F450 the compressor went on it last year (bearing) and we put a new compressor from fords on it recharged the system and it was freezing up the lines would get about 1/4 inch of ice build up and it would stop dripping and the fan would stop as well....

We were busy and it was in September so it never got looked after, well now that its like 90+ I want it working.. tonight I took it out on a tow job it worked flawlessly ... ice cold for 20-30 mins then I had to do a roll over and when I went back in the cab it was not blowing any more so I finished my accident call after the cops left I opened the hood it was frozen from the compressor right to the ac box iced up like crazy I shut it down for about 15 mins and it worked again.. when it freezes up it quits dripping water and the fan is hardly blowing anything... and ideas???

Oh last year I had a bunch of insulation from the bottom of the heater/ac box come off .. think that could have any effect on this problem... the compressor is cycling on and off its not over charged

[GilroyRacing]

Mine is doing the same thing. I replaced the compressor and recharged the system as well.

[Cj Ford]

glad to see I'm not the only one having this issue

I even took it down to 2 pounds figuring maybe it had to much still no good

[GilroyRacing]

Its a PIA, just like you said, it will work perfect untill it has time to freeze up, then it will freeze up and it barley blows any air at all in the truck.

[Cj Ford]

well if either one of us figures it out we will have to share the solution.... I hate driving the wrecker in the heat with no A/C

I will be back at it tomorrow trying different things .. might even call a buddy who is a tech at the local ford dealer if I cant get it figured out .....

the worse thing is the a/c was cold as hell from 1997 when we got it, till last fall when the bearing went you could have the windows sweat on a hot day... just a simple compressor swap and recharge and now its f'ed

[GilroyRacing]

I have no Idea what it is.

I have posted about it before on another site, and still have no clue.



I am hoping some one here will be able to help

[matthewy8]

its freezing up because there is moisture in the system, when you replaced the compressor did you pull a vacuum on the system for about 30-45 min? if you just added refrigerant to the system then you also added moisture. the same goes for the guys that "top off" their systems. to do it properly any time the system is opened up (ex: replacing the compressor) moisture is introduced into the lines etc. through the air (there is always moisture in the air, thats where the humidity comes from) you need to pull a vacuum on it to boil the moisture out because if you dont it will form ice inside the lines when the compressor is running and eventually plug the lines up with ice until it quits working, you will see ice on the outside of the lines where ever the ice is on the inside. you shut it off the ice will thaw and it will work again until it fereezes up again. its also possible a piece of metal got stuck in the line along the way (from the failed compressor) and is causing a restriction that will also make it freeze up. my bets would be that there is moisture in the system though.

[blueovalman14]

also, did ya'll check the temp sensor?? I had a gasser a few years ago the once i recharged the system, it kept freezing/ un-freezing the lines until one of the lines cracked and the refrigerant leaked out.... it ended up being of of the wires got cut in half that go to the temp sensor on the back of the compressor..... just a thought