Hey guys, brand new here. Starting with 1 of many questions ill have in the near future. Summers finally here up north and I've gone a few years with no AC. I figured I'd try the recharge from walmart and see what happens. After adding the can and sealer, I had nice cold air again! This was running in the driv eway of course. On my way to work the next day, it blew really cold for about 10 minutes, and then starts to go back to blowing just ram air. After the truck shuts down and sits for a while, it blows cold at the beginning again, and then goes warm. Do I just need to add another can or is there somthing greater going on here. Thanks!

Dan , (Added only 1 can and had the desired 35-40 psi)

 

It sounds like the system is over filled and the A/C lines are developing frost. Can you get another gauge to verify the psi is accurate? Over filled systems often gather frost or just plain don't work. Been there done that. Good luck.

 

I'm thinking you might have a vacuum problem. Do the vents change on there own when you get on the throttle, does cruise control work, does 4x4 engage properly ? And if the system was low on 134a, there is a good chance a 97 has a leaking evap core.

 

Also consider that if system was empty and at atmospheric pressure, adding refrigerant will not solve the problem. An empty system needs to have a vacuum pulled to remove air from the system before recharge. If there is air in the system before charging, this can lead to freezing up as well.

To verify whether it is "just" then vents as zman said, when it stops blowing cold air, is the compressor still running? Are the lines at the firewall frozen up?

 

Thanks for the reply's guys. Zman- when i accelerate, it changes
To only the defrost vents, 4x4 has always worked without a problem, and the cruise works except for going up hills, it wont downshift, it just bogs down until i either step on the gas or take o/d off. Gd, im not sure if the lines at the firewall are frozen up, i can check that next time i drive it. When it was empty i could always here this cycling noise every 15 seconds with the blower on. This sound disappeared when i refilled the system.

Dan

 

Mine really doesn't like to downshift when on cruise either..... I am not entirely sure what that's all about. Software issue would be my guess.

 

You have a vac leak to start with. https://dodgeforum.com/forum/2nd-gen...ild-vents.html

 

I havent been able to test the vaccuum yet to see which cv has failed, however the line has completely frosted over after about 3 minutes of running