In preparation for a massive road trip in a month I have been going through a couple of things. I want to make sure the A/C is in good shape since it will be HOT!

I have a digital thermo-hygrometer that I used to test the temperature of the air coming out of the vents.

Going down the highway it went as low as 40 degrees, may have broke into the 30's briefly (sticking the tip of the TH in the vent). I don't know how accurate that is.

It is much colder going down the highway, I do know that. It uses R12 and the shop I called quoted me $40/ 1 lb for R12 + dye + labor = $135

What should the temp at the vent be and how do you go about measuring it?

Thanks.

 

Probe - type termometer is what I've seen used to measure. Forty degrees is pretty dang cold. I'd think that should do it.

Mike in Ar

 

hey whats up? 40 deg. is about perfect. i wouldnt do a thing.

 

ya thats a great temp for R12

my stinkin BMW's only blow about 55/60 with 134a but the 2nd gen will freeze your a$$ out in a matter of min!

the one thing you might check is your pressure.. if your low you can freeze up after prolonged use.

 

Well that is the temp I got with the tool I had, don't know how accurate it is. Thanks for the assurance though.

 

If its cold, its fine


My 134a system pushes out about the same temp... It's always colder on the highway cause your running much more air through your condensor, cooling down the refrigerant much better then just using your fan.