A/C glitch?

2001 2.7 4wd 150000 miles

Ok now that's out of the way, I was driving home yesterday 9 hour jaunt in 100 degree heat and the a/c started acting up. It was running fine and it slowly started warming up. I had to run it on max just to stay ahead of the heat, and it was just marginally better than rolling down the windows. This morning I took a look, and its blowing ice cold air now. The hoses on the compressor are nice and hot/cold immediately after starting the truck. I haven't had the chance to drive it for any amount of time, just a quick check to see if the compressor was running. Any thoughts? In the heat of this summer it's been way ahead of the heat, this was an immediate change (say 10 minutes from cold to luke warm)

 

It's possible you frosted over your evaporator. If it's nice and cold now then it's a good chance your freon level is ok. Not positive but without gauges it's hard to be 100% sure. Try running it again and see if the issue returns. If it does then shut off the ac for about 10 min and try it again. Check to see if your ac drain is peeing. Not much you can do yourself except take it in and have it checked. AC is nothing to fool around with and without proper gauges and training it can be dangerous.

 

Aha. I drove it a few miles and it's nice and frosty, and in this heat and humidity it should be pouring water. It's barely dripping out. Where is the drain, and is it hard to get to? The frosting over w/o drawing sounds about right. It went out to pasture about 1.5- 2 hours into the trip.
Thanks!
Sorry for all the typos, these phones are tiny.

 

Hehehehe tiny phones or big fingers heheheh.

The drain is under the truck by the right side of the firewall. If you don't have water inside the truck then the drain might be ok but using some air to blow back through the drain may dislodge any crap in there. Use a restricted blow gun. Also might want to see if your condenser is dirty in front of the rad. There are other possibilities but will worry about that later.

 

Air compressor just paid for itself. It's pouring out after I hit it with a quick shot of air. Hopefully that did it. Thanks!

 

Your more than welcome.

Stay cool hehehehe

 

+10,000

A $20 can of "freon" in the hands of someone who doesn't know what they're doing... even if they are following directions... can create a situation that costs $1500 to fix.



It's hot. AC systems don't work as well when it's hot. Outside air temp directly impacts inside air temp.

It's humid. AC systems don't work as well when it's humid. The wet air does not have as much capacity to pull heat from the condensor, and the wet air flowing through the evaporator leaves it's water behind... and that water drains valuable "cold" right out the bottom of the truck.
But worse, as mentioned, that water can freeze over the evaporator. Now there is no air flowing through it, so it is not being warmed, and the ice problem just gets worse and worse until pressures in the system trigger the compressor to shut down.
This is likely what happened when you went from "cold" to "room temp" in a few minutes.

Once you've put a chill on the ducts, ALWAYS roll up the windows and kick the AC into recirc. It's easier to cool the cooler interior air than the exterior air, and the interior air has already been dried by running through the system so it reduces the potential for icing.

 

I do industrial AC, and a vehicle is a critical charge, meaning you have a real tight tolerance in refrigerant charge where you will cool properly. A car is measured in ounces, the ac in your car may have 12 ounces, your home AC 10-15 LB's, Industrial 25-8000 LB's.
See what I'm saying.

 

First time I used my AC this year it took abot 10 miles for there to be ANY cooling effect. And then, like a switch, it started getting cold. No further problems all summer....odd. Glad you got your situation solved.