AC Question

[turbowarp]

I have an '07 5.9. Yesterday, I let someone else drive my truck. They parked it crooked in the driveway, moved the seat, adjusted the mirrors, left me with half a tank and turned off the AC fan and deselected the AC button.

Today, I get into my truck, start the engine, adjust my seats and mirrors ... then turn on the AC. The fan comes on but doesn't instantly get cold. I hear the engine labor slightly 2 or 3 times (idles down a little) and a grunk noise. I suspect the AC compressor clutch is trying to kick in but doesn't right away. I turn off the AC and back on 2 or 3 times and eventually it catches on and air gets cold. I stopped to eat and when I started it up again, same thing. Cycled the AC on and off a couple of times and eventually got cold.

My Air Conditioning has always been an ice box, except when stopped in our 107 degree Texas heat. Do you think my AC compressor or something is going out? No claims of being a mechanic or an AC guy, but I can turn a wrench. Is there something I can check out and/or fix?

[jcodner]

with the hood up and the engine running turn the ac on and make sure the pulley on the front is spinning. there are two parts to the ac clutch it got the idler section when the ac is off and then when you turn it on it will magnetically pull in and the whole pulley will move. sorry if it don't make much sense.

[bikemancs]

Easy fix, don't let that person drive your truck again!

 

[Austin The DieselTech]

My 03 would do that sometimes but I never had issues with it after that.  Usually when a compressor clutch goes out, the a/c doesn't work at all.  May pull the electrical connector to the clutch and see if the pins are corroded and also check voltage at the harness pigtail.  You should have battery voltage when it tries to actuate the clutch.  Voltage will drop though due to the load of the clutch when it is connected and clutch is engaged.

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[Austin The DieselTech]

One thing you might do is go to the power distribution center find that a/c relay and say swap it with the horn relay if they are the same and see if the problem goes away.  If it does then that relay is going out.  If not then it is something else.

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[Mike]

Just went through this about a year ago, the compressor clutch coil is probably going bad. The truck is seeing too much resistance in that coil so it engages and then disengages but I guess it doesn't always go beyond that threshold and works occasionally. In my truck the a/c would work great...sometimes. When it wouldn't work I would cycle the system off and on until it did work and eventually one day it wouldn't come back on. I went through the trouble of changing the clutch for around $80 and it worked fine for a while and then the compressor died completely (around 6 months I think).
Here is my thread on the clutch issue. http://www.dodgeownerforums.com/smf/index.php?topic=18449.msg257444#msg257444

[turbowarp]

@Mike... I read your thread on it, did you ever do a write on the install? Did you get the repair kit or the whole clutch assembly?

[turbowarp]

with the hood up and the engine running turn the ac on and make sure the pulley on the front is spinning. there are two parts to the ac clutch it got the idler section when the ac is off and then when you turn it on it will magnetically pull in and the whole pulley will move. sorry if it don't make much sense.

Yes, I can see it trying to engage sometimes or engage... depending if it wants to start up or not. Mike below went through this and replaced the clutch coil. I think I am going to visit youtube and learn how to change it. The parts supplier he bought from has DIY instructions. If a shop can change it in 2-3 hours, I figure I should be able to do it in 2-3 days.

[Mike]

The clutch repair kit is fairly simple, 2-3 day job it is definitely not. I can't remember why but I had to drop the compressor to work on it (not unhook the refrigerant lines) which added some time. Once the clutch was apart part of it that didn't come with the kit was so badly worn I had to face it in a lathe so it would make good contact with the new friction plate. After all was said and done it was probably 4-5 hours and because of the wear on the part that isn't included in the kit I couldn't get it within spec but it did work. When I did change the compressor, accumulator and orifice tube it ended up taking only a few hours more than to change just the clutch. I took a few pictures of the process which would help jog my memory a little, I will PM you my #, I am happy to talk you through it via phone or just give you the details of what I did. Being that the compressor went out shortly after the clutch work I wish I had just changed the whole thing instead of wasting half a day and $80 but if you have to pay a shop to do the work its worth the gamble if you are going to try the clutch repair yourself.

[jcodner]

id get the pressures and that checked before ordering a compressor clutch. Your pressures could be down due to a leak or something it only takes 5 minutes to check Im not sure down there but some shops will hook em up for a small fee and let you know

[Austin The DieselTech]

If his pressures were low though, the system wouldn't run due to the low pressure switch being tripped.

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[turbowarp]

A local recommended shop said he'll diagnose it for $20 for me. I am going to drop it off in the morning.

[turbowarp]

I took the truck in to the shop for diagnosis. When I drove it this morning the AC didn't get cold. The shop has had it since 8 this morning and every time they start it blows cold. They can't fix what isn't broke and for them it isn't broken.

[Austin The DieselTech]

Gotta love those intermittent issues!!!

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[Austin The DieselTech]

Next time it does it, try pulling the a/c relay and reinstall it and see if it works.

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