hello everyone. so again the a/c in old green gave out. it has been an ongoing battle over the past few years, but this time I took it to a good friend who has all the right tools as our level of frustration dealing with it has peaked.

we removed everything, and got it all "new" from oh-rye-lees. a new compressor was installed a few weeks back and it worked fine, but cycled very strangely. it would rapidly kick in and out, then just stay engaged. found out the condenser was plugged up and thought maybe that was causing it.

at any rate, it now has a new compressor, condenser, evaporator, drier, orifice tube, and low pressure switch. all the lines were flushed and checked.

it was vacuumed and checked, then charged with freon. the compressor is doing the exact same thing! it is cycling very strange. sometimes rapidly at higher rpm, and sometimes it works just fine. the a/c is working, but it is freezing up the drier, evaporator, and line all the way back to the compressor. vent temps are about 30.

the WOT relay and high pressure switch was replaced, and it did not make a difference. we are at a total loss.

we were told by another person that the clutch on the new compressor was too small and that was causing the issue. it measure 4.8" and we were told is is supposed to be 5.3". is there any truth to that? we just do not know what is causing this, but want to get it right as surely something will break if it stays this way.

sorry for the long post, but we are truly frustrated with this. and yes, we are doing a/c repair in the middle of winter, lol. TIA for the help.

 

Well, we measured the clutch diameter on 3 other trucks and they were all the same. That guy is full of it.

It really seems like the problem is electrical as it does not build more than 100 on the high side.

We will change out the relay, high pressure switch and low pressure switch again and see what gives.

 

Update: it was indeed the relay causing the eradict cycling. It is working properly now. It's an entirely new system and hopefully will last.

 

Dose it still freeze up? Some times the wrong orifice tube will do this.

 

No, it is 100% now. Yeah, a liquid restriction will cause freezing, but that was eliminated. The compressor was staying engaged too long causing it to freeze, and do the rapid cycling at other times.

It was all in the relay.

 

I was going to ask about the Orifice tube, I would suggest if your having any further issues with the A/C (glad it seems resolved at this time) I would look into a SVOV (Its called a Smart Variable Orifice Valve) and it worked I believe on RPM or something like that in a pressure related sense...I will see if I can find the site, that was linked to at some point in the past, might be worth putting one in if you still have the factory original, I am planing on replacing mine when I do the A/C on the truck and the Mustang



EDIT: found the site I believe, here ya go!!!

http://www.acsource.com/smartvov-hig...ficetubes.aspx

 

Which relay did you change? Mine is doing the rapid cycling thing. The Ac is not freezing up like yours, but my compressor is newish, maybe 14-16 months old, and has been doing it since I got it. I haven't been too worried about it, because of all the OTHER stuff that has been wrong in the last couple of years, but if it is a simple relay, I would like to try it.