hey guys, with this heat were having this week I'm desperate to get the ac working in my truck. when I bought the truck last September it had say for a couple months, ac didn't work. they guy said it was the best working thing on the truck when he parked it. I took the recharge cap off and gave the valve stem a little push and she has good pressure, and the compressor clicks on and engages when I turn the ac on. condenser rad gets warm as it should. but not blowing cold. has anybody experienced this before? any help would be great! thanks

 

Check to make sure your heater hose shut off valve is working, and getting vacuum. If this valve does not close and allows hot coolant to enter the heater box, you won't get cold air out of the vents.

Check the vacuum lines themselves. Sometimes they rub through and then can't activate due to the loss of vacuum.

Also pull the glove box and check to make sure that the vacuum pots are activating when the dash buttons are pushed.

 

My 2001 2500 quit blowing from the vents and started blowing from the defroster. Is this the same problem and fix ?

 

You have lost the vacuum to run the mode door. Not sure if the 01 has the same block on the cowl as my 97, but check your vacuum lines from the pump back to the cab.

 

great thanks! ill look into that. if all checks out well Id say I need a recharge. with the ac on for a while the lines going into the firewall don't get cold either. so that being said I don't think the system is working properly.

 

The high side will be HOT, and the low side should be COLD. If the lines are not getting to those temperatures then there is probably a lack of charge in the system. Probably enough pressure to activate the switch, but not enough to do any major cooling.

 

Hook some gauges up and get low and high pressure readings. Also make note of ambient temps. when the gauges are connected.

Are you using R12 or R134?

 

r12

 

Wish I had R12. Either way, get some gauges hooked up.

I hope you have some R12 or have access to some. If not, get you 609 cert, then you can buy R12.