Ice cold until I accelerate up a hill or speed up, release gas pedal and it blows cold. I installed a vacuum can thinking that would help no luck. Is there a check valve or something I should be looking for.
Thanks in advance, Dennis

 

R u saying it stops blowing cold or r u saying it stops blowing out the dash vents?

 

Stops blowing cold air period when I accelerate. When I decelerate it blow cold air again. Acts as if you turned a switch off and on.

 

Your problem is almost certainly loss of vacuum when accelerating. When this happens, the air flow defaults to the defrost vents and seems to stop completely.

Follow the vacuum line from the reservoir ball back to the firewall. The most likely place for a damaged line is in the battery area.

 

Does air (hot, cold, whatever) continue to blow out the dash vents when u accelerate or does air period (hot, cold, whatever) stop blowing out the dash vents when u accelerate?

 

Thank you for the advice re. the vacuum line near fire wall. I thought there might be a check valve somewhere.
Dennis

 

I'm awarding you 100 points for trying really hard on that one For some people, specificity is a real biatch! Nothing like asking pertinent questions and getting ambiguous responses from folks.

 

Mac, do you think. I was ready to break out my thesaurus, I thought I lost the ability to communicate. I'll take 95 and give the 5 to help someone get started.
Thanks for your support.
Dennis

 

If you are interested in examining the HVAC/Cruise Control vacuum tubes in the engine bay go here.

https://www.cherokeeforum.com/f2/gre...e-6558/index4/

Review post #51.

There are two check valves, as shown in post #51.

 

Ken Thank you Dennis

After reviewing your Diagram, I didn't have one[check valve] replaced engine with Chevy V8 Threw all Jeep stuff away. Can't teach amateurs much. Folks like you make me look good

 

Um...
Actually, I was awarding the points to djb383. He was trying to ascertain whether, while accelerating, you were losing ALL air out of the dash vents, or if there was still air, but it was just no longer cold. A correct description of which leads to very different troubleshooting steps.

A loss of air of any kind (hot or cold) out the dash vents is almost always indicative of a vacuum leak issue.
When you have air still coming out the dash vents, but it stops being cold, that is indicative of other problems. Possibly a slipping compressor clutch.

He was trying to get you to be specific on that point so he'd know which direction to point you in. Perhaps you caught onto that, but your choice of words in your response was still a bit ambiguous. No big deal. The whole interchange was kinda funny. Sort of a "Who's on First" routine.

At any rate, glad you got you issue fixed. It's always amusing to see how well (or poorly) things translate on the interwebs