I want to do my own repair work on my 1994 Ram 1500 4x4 air conditioner, one to save money, and two so I can become more DIY proficient. I don't know what's wrong with the AC yet, just that it's not cooling at maximum efficiency. Temp out of the vent only reaches 50 degrees and that's only after driving for 30 minutes or so. I don't have access to the big dollar refrigerant reclamation device. I do have a set of gauges for 134a, and am looking at buying Harbor Freight's $104 2.5 CFM pump, or one at a pawn shop if I can find a decent one.

My questions are, how do I depressurize the system in order to work on it once I figure out what I think is wrong? And, am I correct in thinking that regardless of what component I have to work on, the system needs to be depressurized?

I've never done any AC work before and am tired of paying others to do what I think I can do myself with just a little help from The Forum.

Thanks in advance for your advice and help.

 

Put the gauges on it, and see what they say. Might just be low on refrigerant.

 

If I read the gauges correctly when I checked it last weekend, 33 on the low side and 250 on the high side with an outside temp of 80. I'll go check again and attach a photo of the gauges. It's 104 outside right now.

 

Nice and toasty warm......

Grab the 95 service manual from the faq section. There will be a chart in there for pressures vs. ambient temps. I do think you are just a bit low though.

 

the high side should be about 250 and low side between 40-45 at that temp.

 

My mistake in trying to remember last weeks readings I reported in my earlier post because it wasn't right. It was actually 52 and 220.

Regardless, today's readings are as follows:

High side: 265
Low side: 55
Ambient temp: 105 degrees (at 7 f'ing o'clock pm but only 32% hum)
Vent temp (with windows open, doors shut): 58.7

I can't upload my photo of the gauges from this iPad for some reason but that's what the readings were.

So if I read the FSM chart correctly on temp and pressure, I'm slightly high on my low side pressure, and within the range on the high side. And my vent temp is within range. So I guess I don't have a problem?? Heck I don't know. All I know is I want icicles hanging off the rear view mirror. Is that too much to expect from an 18 year old truck with 223K miles on it?

 

yea i was told anything under 30* below ambient temp is good for inside air, my truck only got down to 62* when it was 105 outside, im in arizona so i feel ya

 

58 degree air with ambient of 105 is pretty good. About as good as you can expect.

 

That temp sounds fine to me. Pressures sound good as well.

 

+2... And with AC on max, the windows should be "closed" to check temp (at the upper dash vent).