A/C blows cold when under hard acceleration

[GoTerry]

‐ This is weird, A/C doesn't work one day, after replacing clutch and running a radiator comb thru the fins of the condenser, I topped up the refrigerant and it seemed to work fine. 

Fast forward to next warm season and it wouldn't work... after checking everything and finding nothing wrong, it was by accident that I stomped the accelerator to the point of kick-down and the A/C blows cold.. but only for a while and then back to nothing but warm air.

I'm at a loss, thanks in advance. 

Terry

Btw it's an 89' C2500 5.7 automatic 

Edited April 24, 2021 by GoTerry

[CamGTP]

You're going to need to hook up the truck to a AC machine to see if the system is working within the correct pressures.

[GoTerry]

Thanks Cam,

I was the body shop guy in the family, my brother was the wrench, when he threw gauges on it (old school, I know) I recal either 5.1 or 5.5? He had said that was a tad high but should work fine... he's 6 hours away or I'd go there but cant anytime soon, we did talk about it but he suggested putting on an electric fan to push more air across the fins... that didn't sound like it was the actual problem or he was just spit-balling.

So was the gauges what you meant or is there a machine that will diagnose the electronic control box.

Thanks again for your advice 

Terry

 

[Brian Lindsey]

i would check your fan clutch, sounds to me its going bad, when you kick your truck into passing gear the fan will turn much faster, even when clutch is not working

[GoTerry]

I never thought of that... thank you.

My brother arbitrarily offered up adding 2 electric fans but never said why - makes sense, I'll check it out