Auto air conditioning

[soldier-of-the-apocalypse]

I have a 93 dodge ram with cummins and the A/c worked great last year. Now this year it's not working and its starting to wear on me. So today I checked the freon and its full. The compressor just cycles on and off and it's not blowing cold. Any ideas?

[cofi]

You checked the Freon??? What psi was your system running at???

[soldier-of-the-apocalypse]

120 psi when the compressor was off then when it kicked on it was at 55psi

[sniper7]

I think your truck is confused and thinks its a ford so it doesn't work right!


I'd probably try a bottle of freon just in case.

[soldier-of-the-apocalypse]

Well it does have over 350,000 miles so it definatly doesn't think it's a ford lol

[trlcavscout]

Could be a bad high/low pressure switch, or a few things I wouldn't add freon before getting it checked.

My brother is "that guy", of course he owns a dodge and it always has problems. But he will spend hundreds of dollars and waste countless days self diagnosing and replacing parts. Then he bitches that he spent hundreds and it still isn't right HAHA! Pay the diag fee and save money.

[anomad]

The ac on my jeep is fubar and we hit 103 today. I said a few bad words.

[tmleadr03]

120 psi when the compressor was off then when it kicked on it was at 55psi

Low side right? Pressure readings should be between 25 and 40 psi on the low side and close to 250 on the high.

What your saying if i understand correctly is that it turns on, the pressure drops to 55 and then it turns off and the pressure goes back up to 120? I need to see the high side pressures to know but I bet you have a restriction on the high side.

[soldier-of-the-apocalypse]

I'm pretty sure it's the low side. It's a r12 system and there is a large valve and a small valve and I used the large valve since I just ave standard home ac gauges and that's what fits but I'm not 100% if I used high or low

[tmleadr03]

I'm pretty sure it's the low side. It's a r12 system and there is a large valve and a small valve and I used the large valve since I just ave standard home ac gauges and that's what fits but I'm not 100% if I used high or low

R12? Really? Never been converted? My pressure numbers are off it is really is R12, that is a lower pressure system. You are going to have some trouble getting someone to work on an R12 system with out wanting to retrofit it to R134.