hiluxhack

The drain tube is working and I blew it out with air nozzle just in case. We've had temps in the upper 90s but the air is blowing cold. It's not dripping much, just lots of condensation on the box. Any ideas what's causing this? The carpet gets damp on long drives and it's just a nuisance. Nothing like mildew to make a clean truck smell like a turd. Well, I guess a turd would too.........sorry.

scope103

Are you getting condensation on the OUTSIDE of the Cooling Unit case? Could be that the evaporator is TOO cold, due to slight under-charge, or perhaps bad Expansion valve.

You can't really measure the temperature before and after the expansion valve (as it is inside the case when the AC is running), but you can measure the temperature rise between the center duct and the suction tube right at the firewall. There should be a 0-10°F temperature rise; outside of that range suggests a problem.

Terrys87

iTrader: (1)

Just because your drain tube is clear, I have seen it clog back up inside the evaporator. You may have a lot of debris in there and it is holding water instead of draining out thus causing condensation on the outside of the box or leaking out of the evaporator box.

Some signs to look for is the cowl in front of your windshield full of debris. Blower motor having debris in it. Take off your front mud flaps, and pull the inner fender forward enough to see inside the fender. Is it full of debris? If so, what has happened is the cowl got so full of debris and it has drain holes on the top of the cowl and debris has fallen down to the inner fender.

Also on the passenger side there is a stove pipe that is to keep the debris from falling down into the blower motor and then the blower motor blows the debris to the evaporator. Below is what I commonly see in trucks that are in wooded areas and the picture doesn't show how bad it is in some cases. Only real way of getting it cleaned is to pull the evaporator and wash it out. A little more information if you want to check it out. https://www.yotatech.com/forums/f199...l#post52151096 You will need to scroll down a little bit.

The bottom of the evaporator box is so full of trash that it just cant drain.
Half of dirt I pulled out of Evaporator.


This AC system is charged, so I will just get a vacuum cleaner in there to get the other half out. This is from not having screens in the windshield cowl. Just posting to show what could be some your problem with your AC.

hiluxhack

Thanks. I'm leaning towards low 134a also. Just certain signs like fog from vents occasionally and slightly warmer performance from the a/c. As I said, it's very hot outside so I wasn't sure how much that was effecting cooling but now that u suggested low freon, I agree. I'm gonna put gauges on it. I'll report later.

hiluxhack

UPDATE. So I got checked the a/c system pressure, sure enough it was a little low. The compressor cycles normally and it blows cool out of the vents. It's been so hot lately that I didn't expect ice cold. Topped off with a can of 134a. Ice cold. It sure helps to bounce stuff off you guys. Sometimes I miss walking around the shop doing just that.......Then I look at my twisted, scarred fingers and I don't miss much else. Thanks guys. I appreciate every reply.