After about 2-3 hours @ hiway speed, the a.c. starts getting warm, If I stop & shut down, about 2 gal of water runs out, indicating a BIG ice block. If I don't stop & just turn on the vent (no a.c.) it thaws in about 20 mi. Anybody had this problem & what to do about it?

sound silly but the freon may be leaking very slowly r134 tends to get colder as the pressure decreases. either that or the orifice tube is not working correctly.

Does yours have the in cab air filter system, the filters are located on the passenger side on the cab side firewall. If so have the filters ever been changed? I have to replace my filters about every other year. The restricted air flow can cause the freeze up can't it?

After about 2-3 hours @ hiway speed, the a.c. starts getting warm, If I stop & shut down, about 2 gal of water runs out, indicating a BIG ice block. If I don't stop & just turn on the vent (no a.c.) it thaws in about 20 mi. Anybody had this problem & what to do about it?

Same problem last year for me. Keep the fan on med-high or above and on fresh air, not recirc. Works.

never had it on my 03 but my dads 01 has that problem on our road trips and would ususally only happen every 5 hours. We just pimp it with the windows down for a little while.

Had this problem on mine, as well as on a previous vehicle.

Pressure cycling switch on the side of the accumulator.

I am not an AC expert, so I may have the accumulator name wrong; the device I am referring to is the silver, insulated cylinder with the AC lines entering and exiting, which hangs off the firewall, adjacent to the fuel filter.

Changing switch is a very inexpensive, two minute repair.

It sounds like the coil was definately iced up. You might want to pull your box in the cab apart and check for dirt and other goodies. Had a simlar problem on my buddies 1500, when we pulled the box apart to put a new heater core in it, we found all kinds of paper and other goodies. Looked like some mice may have made their way in there. The coil would cool the truck, but turn the fan down, the debris would hold the water and freeze. Might also be a good idea to have a tech check and see what pressure the system is operating at. An easy way is to start the truck, crank the AC full blast and watch the compressor for a few minutes. If it starts turning on and off, it means either the referigerant is low or the pressure switch HoustonDmax was talking about.

Spent my whole life working with ref. cases in grocery business. When a case iced up it was low on refrigerent. Sounds like same kind of deal.

Last year out west, mine exhibited the same characteristics. Low air flow over coil, resulting in freeze up. change your cabin air filter first. If still freezing up, have AC specialist check accumulator for higher amounts of oil, and a blocked needle valve. Mainly, the cabin air filter. My fifth wheel will freeze up if the air filter is not clean or changed frequently.

There use to be a little right angle drain on the older vehicles. I just looked and there is one on my 04. Pull it off and make sure it is clean. Its on the firewall behind and below the fuel filter.

Change the low pressure switch

Spent my whole life working with ref. cases in grocery business. When a case iced up it was low on refrigerent. Sounds like same kind of deal.

I agree it might have something to do with refrigerent level. That is a one minute check, have this done first before you start ripping things apart or spending any money. Anyone who works with refrigerent knows this and will do the pressure check first.

Good Luck

I agree it might have something to do with refrigerent level. That is a one minute check, have this done first before you start ripping things apart or spending any money. Anyone who works with refrigerent knows this and will do the pressure check first.

Good Luck

X3
Has a refrigerant leak somowhere. Have it checked. Suggestion- look at compressor and see if it has gunk built up around the center where the two halves come together.

Had this problem on mine, The inside filters were full of dirt. The dealer change the filter and replaced the pressure cycle switch. It works great now!

Definitely change the interior filters if you haven't. Low air speed will cause an ice-over too. If that doesnt work, move on to the charge and low pressure switch.

This sounds right on the money.

Spent my whole life working with ref. cases in grocery business. When a case iced up it was low on refrigerent. Sounds like same kind of deal.

:help: when changing this switch do you have to have the system emptied and then refilled ?... or can you just change it and not have anything leak out?

Anybody know how much these switches cost? :)

No need to discharge and recharge. Simply slides over a couple of prongs.

I don't remember mine being very much. Maybe in the $20 range, but don't hold me to that.

I will say that changing the switch has worked on more than one truck for me. Seems to be a fairly common problem?

Thanks HustonDMax for the info :cool2:

Found out nothing wrong with the switch or the AC level...

well it turns out that I have in cab air filters and I didn't know it ... my mechanic friend said I did have them and sure enough he found the door ... I had looked but I couldn't find it .... of course not having changed them in almost 5 years didn't help my AC ... you should have seen how black and full of seeds they were -:t ...supprised any air was getting through there ....the AC works great now that it is getting air flow across the coil.;)

I changed my cabin filter recently and found the same disgusting build up of dirt and debris. From now on, a filter change is a part of spring maintenance.

Glad your problem was the simplest cure of all, too bad they all can't be that way ;)

Yeah, I too learned real quick once I saw the mess in there :rolleyes:

The funny thing was that none of the dealers knew anything about this and even when I bought the truck I went through all the brochures and manuals and it all keep saying Crew cab only nothing about extend a cab :(

Oh well I know now and all is working just fine. :cool2:

Just wanted to mention that those cab filters are washable. I've done mine 3 times now, and IMHO they come out good as new. I am just judging that by the looks. If there is some special coating, I'm not aware of it.

Mine does the same. I checked AC charge and I'm good there. Replaced incab filters about 6 months ago (8k miles) so I think I'm alright there. Looks like a trip to the dealer for the AC pressure switch unless someone has a different suggestion.

Also, I've checked the drain tube and it appears free of obstruction...after I stop from a trip running the AC the tube pukes about a gallon of water, I mean there is a big puddle. Thoughts?

Same problem last year for me. Keep the fan on med-high or above and on fresh air, not recirc. Works.

yes, the manual says to only use recirculation to get the cabin your desired temp, then switch over to reg AC...otherwise, this will happen...happened to me on the way to Texas from Arizona...

Mine does the same. I checked AC charge and I'm good there. Replaced incab filters about 6 months ago (8k miles) so I think I'm alright there. Looks like a trip to the dealer for the AC pressure switch unless someone has a different suggestion.

Also, I've checked the drain tube and it appears free of obstruction...after I stop from a trip running the AC the tube pukes about a gallon of water, I mean there is a big puddle. Thoughts?

Mine does the same thing .... lot depends on how humid it is outside on how much water comes out ... mine still works great and doesn't seem to ice over ... mine has done that since day one ... the only time it iced over was when I had not changed the filters ... once the filters were changed that was the end of ice over ... still get a lot of water again depending on the weather.

But keep us informed ... would be nice to know if changing the pressure switch fixes the puddles.:rolleyes:

if you are driving with the recirculate on all of the time, it's gonna ice. It says in the manual to only use recirc for getting the cab to the desire temp, then switch to regular.

Mine is doing the same thing thanks for all the info, thought it might of been over charged, Liked the windows down PIMPIN cause that was me):h