A/C thread

[Brooklyn Tow]

OK two problems.....Changed all the lines that got damaged from the accident. The big top line that goes from the compressor to the bottle/dryer, I replaced that with a line I had from the 99-2000 sub gasser, it looked pretty much identical and bolted right on.

Turns out when I put the new condensor in it had/has no orifice valve.....will the system operate without the orifice?

Also when I went to charge the system it took freon (134a) started to cycle but didn't seem to circulate then the compressor stopped working and the head unit shorted out.....replaced the head unit, same deal compessor started to work but not seem to circulate and shorted out head unit 2.

Is it the big line I put on is wrong/clogged high/low pressure switchs are bad? the compressor clutch has a little wobble to it (from the accident I guess).....could the internals of the compressor be pooched and not letting the gas circulate and/or can the compressor be shorted as to be burning out the 2 head units....It's hot and humid in NY and before this accident the A/C worked fine.

HELP!

 

[THEFERMANATOR]

First you gotta get the orifice in the condenser or else she'll never cool down and just circulate the system, or even worse liquid lock the compressor and blow it out. As for your control head, it doesn't carry the current to the compressor, so I don't see how it could get shorted out from the compressor. Sounds like maybe you have a chafed wire somewhere from the accident that is causing issues.

 

[Brooklyn Tow]

But the compressor shuts off when the head unit blows or the head unit blows and shuts the compressor down......More than that when the head unit blows all the contros are inop, only blows from the bottom and the A/C button and recirc are dead.

Can the compressor short internally and blow the head unit?....Can the high/low pressure switches be blowing something?
The clutch pully on the compressor has a little wobble, but still engages, spins and took the gas....Is that something else to contribute?

And the no orifice tube deal.....You said, "liquid lock".....but I don't think the freon is even circulating....What do you think is stopping flow,....Orifice, High/low switches, the top hose/line I took from the gasser (maybe it's clogged...IDK the history), or the compressor itself?

Where to start??????...and remember I'm blowing head units like crazy (EXPENSIVE)....any way to test without the head unit, so I can see the system is working correctly without having to worry about the head unit???

Should I use a orifice or a VOV thats been disscussed here with mixed reviews?

All input is greatly apprieciated and NEEDED

 

[Acesneights1]

OK ...where to start...First off what do you mean your "Blowing" head units ? You got me a little lost there. If there is a short I would "think" the fuse would blow. Ferm is right you NEED the orifice tube. It makes the whole system work and causes the pressure differential that creates the cooling. Bottom line, you need it so that is first. as far as the VOV I have never personally used one so I won't say bad or good on it. I know the Factory euipped 134a systems on our trucks IMHO work pretty damn good so I would go with factory but that is my opinion nothing more. The compressor itself has no electric parts. The Clucth that engages it is a giant electromagnet and I could see that shorting and blowing the fuse maybe. I am not all that versed in the wiring on these and won't pretned to be but I "think" on some it runs through the ecm. If someone knows more, feel free to correct me. I would start with basics. First of all install an orifice. That needs to be first step. Second unplug the compressor and the swiches and then see if the control head "blows"(I am still confused on that one a little. Perhaps better descrpition). Do you have guages ? Prepare to replace the high side port. IN fact might as well get one. It can bechaged with a crescent wrench but be careful it distort real easy and LOOK at the new one first before wrenching o the old one. You don't put the wrench where you think you would. I ruined a line years ago to learn that leson. As far as the line you used goes if it fits, it works. Period. You could even temporarily jump the sensor on the back of the compressor. The can be removed with a snap ring. It sounds like you have a short in the wiring somewhere. Accidents suck.

 

[Acesneights1]

Also if there is a short it would most likely be at the compressor. I dount the switch would cause it. I short is a path to grond for the b+ . A shorted switch would most likely cause cycling problems not a dead short. What side of the motor does your compressor mount on pass or drivers ? I have the drivers side one off the dually. The clutch is a little sticky/rusty and needed a whack once in a while but it works if you need it. I replaced the whole thing cause it was only 30$ more than just a clutch. Let me know. I can ship it tommorow if you want it.

 

[Brooklyn Tow]

Head Unit = The controls in the cab....Hot to cold knob, Floor to vent to defrost knob, and the blower motor speed control.

When I said the head unit "blew" or shorted out, I knew this was the case because when I swapped the one from the gasser burb in, the exact same thing happened,....Everything was fine, (Meaning the air path knob worked, the a/c button and recirc button lit up and worked and then..."NOTHING".... The compressor stopped cycling, the A/C button and recirc button are dead and the air path knob doesn't do a thing, it'll just blow from the floor.

But again, when I first started to charge the system, the compressor was taking the freon but it wasn't going anywhere else....The bottle/dryer didn't get cool/cold, nothing....but this was "before" I found out I didn't have an orifice tube.....What exactly happenes when you try to charge and run a system without an orifice tube?

 

[Acesneights1]

It will take freon but nothing will happen.

 

[Acesneights1]

here is a crude pic of how it works....basically the refrigerant is just going around in circles. You won't hurt it but you will not get ANY cold.

 

[Acesneights1]

Try to think of it this way, If you bust the nipple off an air tank and the air comes screamin out the nipple gets cold right ? Or if you opened and oxgyen bottle under pressure and let it fly the valve would get cold. When you pressurize a gas it gets hot. When you release it , it gets cold. The orifice is causing basically a nessicary restriction.

 

[Acesneights1]

I really don't get why you are burning up control heads though. I would think if there was a short the fuse would blow . That is a weird one but I would probably look at the compressor clutch espcially if it's wobbling and you are certain it got hit. If you can get your hands on another control head try it with the compressor unplugged.

 

[Brooklyn Tow]

Very late update:

http://www.thetruckstop.us/forum/sh...ound-Stud-bolt&p=345415&viewfull=1#post345415