Any AC Experts?

ToMang07 · Jul 14, 2016

So this spring, my AC clutch did this, once. I got it on video after a short heart attack (I though I had a rod about to go....PMRs)

http://www.youtube.com/watch?v=eP70fDEvrT0

After that, the AC worked for a little while, then quit working on AC/MAX AC settings. Compressor was still coming on in "vent" as it always did. Then about a month ago it quit all together.

I tried recharging it. (Worked for a couple hours) Let a little Freon out...by mistake...:lookaround: tried refilling it. Nothing. Every once in a while it will occasionally work for a few minutes, then nothing.

I suspect the compressor/clutch is bad, or in need of adjustment. Anyone had a idiot guide on how to troubleshoot/diagnose it? I'd rather not pay for a $300 AC service, at least not until I know I have to.

Good think it's only hot up here a few months out of the year. Although driving in SC really sucked a couple weeks ago, lol!

Thanks in advance.

79jasper · Jul 14, 2016

No guide, and not a expert. Lol
But you can try jumping the low pressure switch to see if it runs constant. Could be one of the switches, or the clutch is just going bad. They have to be shimmed to a certain gap.

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Justin@DP-Tuner · Jul 14, 2016

Do a Google search for 7.3 AC air gap. You will see many resources on how to check it and make sure it is in spec.

If it is not that, I bet it is the low pressure switch.

Try wiggling the switch when the truck is running and the AC on. See if it makes the clutch engage and stay engaged.

DEEZUZ · Jul 14, 2016

really need to get a set of gauges on it to see what shes doing

Arisley · Jul 14, 2016

I second what Justin is saying.

Also, that little center nut on the clutch, you can pull it off, there are some spacers behind there. I removed one and fixed my issue that looked just like yours. I didn't know anything about how it worked, did not measure anything. Removed a spacer (looked like a few washers stacked up together), started working fine.

A year or so later, issue started again, wiggled the connector that Justin is talking about, and it started working. Replaced the connector (thought it was the wires), no change. I was skeered to remove the sensor, thought I would lose Freon, nope, there is a Schrader valve behind the sensor (great idea, some engineer was on the ball that day), replaced it, no issues since then.

TyCorr · Jul 15, 2016

It seems the majority of the time its the damn high pressure switch. If not that the clutch is getting loose.

ghohouston · Jul 15, 2016

ive had luck removing the shims before on a 6.0, its worth a shot.

ToMang07 · Jul 15, 2016

Thanks fellas. I'll try the shim first, then the pressure switch. :toast:

8WR_ZJ · Jul 15, 2016

That is the a/c clutch rather it be the air gap or the actual clutch mechanism is gone. It is to rapid to be pressure related. It could possibly be the power switch but I have my doubts. Also this is exactly what mine was doing on my 6.0. I took off the nut and there was about 3 small shims under the front plate. I removed the thinnest one and all was well when i reassembled it. On the 7.3 the gap should be between 0.35-.75mm or 0.014-0.030 in.

ju015dd · Jul 15, 2016

Def try to remove spacers before since it is so easy. I had to do this last year and mine has worked flawlessly since.

ToMang07 · Jul 15, 2016

Sent from the pocket porn device!

ToMang07 · Jul 15, 2016

For those of you that removed a shim...how the hell did you get the bolt out? And is it a standard or reverse thread?

Put the AC refill on it again today, it tool a little more Freon, but it made no difference. Took the plug off and jumped it, didn't make a difference, either, so I don't think it's the pressure switch.

http://www.youtube.com/watch?v=9nXK6NSvz38