I have a 1998 Ram 1500 Laramie with the 5.9L engine. A/C doesn't blow cold at all. I got the DIY recharge kit, plugged it in, it read zero. I started to charge it. Relatively quickly, it starts reading about 45 psi, and the compressor starts cycling on and off every few seconds. When it's on, the reading drops to about 5 PSI -- cycles off, back up to around 40-45 psi.

I'm assuming this is because there was no charge, and the compressor is cycling off to avoid damage? I just need to keep dumping refrigerant in?

Other question: Everything that I've read, online, in the Haynes manual, on the A/C charge folks website, says the low side port is at the front of the engine compartment, behind the passenger side headlight. BUT, that one has the "H" cap on it, and the recharge kit does not fit. Behind the air intake, towards the back of the engine compartment, is a hose with an "L" that the charge kit fits. But according to everything else, that "should" be the high side port.

Any ideas what's going on here? Is this year/model different? Did some hack job mechanic put it together backwards? Do I need to haul it into the shop, or should I just keep putting refrigerant in til the compressor stops cycling, and call it good? Thanks.

 

My low side port is on the passenger side towards the back as well. No worries there. I think maybe you received some faulty information before...

As for the AC pressure...you should be seeing much more than 5 psi when the clutch is on. When the clutch has cycled off, then the pressure should reach much higher (maybe 80-100 psi?)...sorry but I cant remember the exact numbers here. I do know that the clutch shouldn't have to cycle every couple seconds...there should be longer intervals than that. You need to put more freon in there until the clutch stays on for a while longer.

 

Should be a chart on the can that came in the kit that tells you what ideal pressure should be vs. ambient temp.

 

When first refilling after it's low, the compressor will cycle on and off until the pressure is enough to keep it on all the time. Just keep filling it up to the max the system holds. (should be a sticker under the hood stating how many ounces it holds)

 

Thanks guys.

Now, following on to that question: My low side port seems to be leaking. I can hear/feel gas flowing from it. Can I replace the entire service port easily? Or is there a better option?

 

Schrader valve is what ur lookin 4 autozone has them
it will let all the freon out when u change it so get another can

dirt gets in them you might be able to put the can connect on it n take it back off and the dirt might dislodge

 

If you're changing the valve you'll need to pull a vacuum on the system before putting freon back in.

 

Thanks all. I got about 20 ounces of R134a into the system. It seems that the port cap is sealing the the leak, and it's blowing cool-ish air now. I know it's way under-filled from the recommended 2 pounds, but I don't want to overcharge it. It'll get me by.

It's going in to the dealer soon for some recall work that the previous owner never took care of. Just gotta wait for them to find the blueprints and make the parts I need, lol. I'll have them check out the leaky port, and do a proper suck and fill when it's in there.

 

The low side port was leaking on mine as well, I picked one up from a pull a part (the inside part screws out). I did not pull a vacuum and just refilled it. May not be best practice, buut mine's been blowing cold air for two summers now.

 

I have a 95 cummins AC system is low on freon. My problem is I can't find the low side port. I have looked at the accumulator and the line to the compressor. There is no charge port on the low side anywhere. How do you charge these systems?
Thanks