A couple of days ago I noticed my AC was blowing warmer air when I was sitting at a red light and would get noticeably cooler once I get moving down the road again. I do have a low side gauge from one of those DIY recharge kits, it showed about 50 yesterday when I checked it and the temp outside was about 75. I know the gauges are not the best way to test but it is all I have on hand here at home. My e-fan is turning soon as I turn on the AC. My engine is not overheating so I don't think the fan clutch is bad. It should not be bad, it is a genuine OEM Mopar fan clutch, I think I paid $120.00 for it in the summer of 2010.

Any ideas or anyone here had this problem? If so what was the fix? Compressor getting weak? i replaced the compressor about 5 years ago with a new Napa compressor. My OE compressor was working fine but had a bit of a growling noise so I replaced it as a preventative measure. I had the freon evacuated and recharged in 2010. I don't see any evidence of a leak but that does not mean a leak does not exist.

I am going to check the whole system this weekend, may even splurge on a cheap set of AC gauges. Thanks for any help.

Jimmy

 

that is pretty normal for the a/c to blow warmer air while sitting at a light, if fact i've noticed that manual transmissions more so that automatics. the more of a load on the compressor, the more efficient of heat transfer you will have.

the pressure sounds about right to. you should never have to add any refrigerant to the a/c system. unless there is a leak. then you might as well find the leak and fix it. otherwise you will just loose the refrigerant again.

 

It's not normal for the a/c to poop out sitting at lights. I live in a hot place, like you do, and sitting at lights in 100 degree plus weather would be impossible without good a/c.

Instead of splurging on a set of cheap gauges, Harbor Freight has them btw, use the money to take the truck to a place that does a/c system diagnosis. If the pressure is okay, it could be something as simple as a faulty low pressure sensor. But almost any in system problem will require evacuation, pulling a vacuum, and installing new R134a.

You should be able to get the thing diagnosed for under $40. Beats throwing money at it with little or no result. Good luck.

 

Well I live in Gilbert AZ

And I know what you are talking about

To my knowledge for this to happen either you are not getting a good air flow through the condenser by the (Efan or belt Fan) or you have a pressure problem you may have too much Freon.

Have you had the system open lately?

Have you cleaned all the bugs off the condenser this year?

You could check too see if any auto parts shops have the gauges for rent some do

 

I've had a/c systems that acted like that before that were just low on refrigerant. Does your compressor short cycle while you're using the a/c? That would be good indicator of low refrigerant. Just using a gauge won't give a good indication of the amount of charge you have. When they recharge a system, they charge it by weight and not by pressure. If you find that the charge IS low, have the system evacuated, checked for leaks & fix as necessary then recharged. It's the only sure way to make it right.

 

50 is a little high for 75 outside temp but those cheap in can gauges are not accurate at all so you could be ok.

 

I had the same warm AC at idle coming home today. While sitting still I revved it to 1500 for a minute, AC became markedly cooler. I checked the fan clutch, it appears to be OK, only moves a couple inches when I give it a good shove with my hand, still feels nice and firm. The fan clutch also still engages for the first 1/8th of a mile each morning when the truck is cold and I am headed off to work so I believe it is OK. I can almost smell a burning odor around the compressor when the engine is running and AC is on. That may be just heat from the engine but I never noticed it before now.

I checked my file of parts receipts and the Napa compressor I put on back in 2008 only had a 2 year warranty, long expired now. It was also a reman, I could have sworn I bought new but the receipt says reman. So I will try to check it further tomorrow but it looks like I need a new compressor. I think if it were low on R34 it would blow warm air all the time. When driving it it cool but not as cold as it was just last week. Up until now I have had no AC problems at all since 2008. Thanks for the help and ideas here.

Jimmy

 

If you smell something burning near the compressor clutch the clutch itself could be slipping.

We need high and low pressures if you can get them to diagnose the system.

Overcharging is as bad as under.

 

I am going to get a better look at it tomorrow. I probably will need to get it checked out before doing anything else. I don't have the technical skills to read a set of gauges, even if I owned or rented a set. There is a good independent garage near my house. They are the same guys who installed my catalytic converter assembly, I will let them check it out. I know I can trust them not to rip me off. AC, like exhaust is probably best left to a pro who knows what he is doing and has the right tools for the job.

Thanks.

Jimmy

 

If you have too much Freon in the system the compressor will need to work harder and the clutch will be under more strain to stay in solid contact.

You can also damage the compressor with too much Freon in the system that's why you should be on the low side of the pressure scale not the high side.

I had problems with my setup last year and had a shop check things out he let me watch all he did was to insert a temp gauge in the main vent set the A/C on high and slowly pumped more Freon in the system till the vent temp reached the maximum temp it should reach he never used any gauges at all.

You should never have the Idea that more Freon is better it’s not… shooting for a reading on the low side always works better.