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Discussion Starter · #1 ·
My air conditioning compressor won't kick on... is there something else i could check other then replacing the whole thing.

How do i put what truck i have under my name...

94' dodge 3500
 

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push in on the schrader valve in the line(by the fender or the dryer) and see if there is any freon in it it will not turn on if it is empty or real low
 

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Discussion Starter · #3 ·
yeah i did that and the guy i just bought it from had way to much anti freeze in there when i put the guage on it read in the warning. I just bought this truck and the AC worked for a day or so and it just quit and i don'tk now anything about AC stuff so when i took to the guys at the auto parts store they found that it was way over full so they let a lot of freon out until it was right and then realized that the compressor was kicking on
 

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Well if you DO have freon in it and it Is in the right pressure range, then it Should kick on. If it doesn't, your high-low pressure switch is either bad or the wire connector is not connected properly. It should be a 2 wire plug coming off a nib attached to the metal tube just off the back of the ac compressor... Right next to the oil filter.
 

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Discussion Starter · #5 ·
Okay here's the newest that's right it is a wiring problem bc I took it to a guy today and only one of the parts where my ac relay goes is hot rather then two. When we put a paper clip on the hot and a ground the compressor kicks on and my ac blows cold. So my compressor isn't broken. Now where do I start looking for wires? Behind that compressor like you said?
 

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Yeah, at least find out if that high low switch is working right. That switch might be what controls tha master relay for the ac clutch. If that switch doesn't work, it won't tell the relay to turn the compressor on
 

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yeah i did that and the guy i just bought it from had way to much anti freeze in there when i put the guage on it read in the warning. I just bought this truck and the AC worked for a day or so and it just quit and i don'tk now anything about AC stuff so when i took to the guys at the auto parts store they found that it was way over full so they let a lot of freon out until it was right and then realized that the compressor was kicking on
The guage is gonna read very high when the compressor isnt running. The compressor while running is trying to pull the lowside into a vaccum. FYI id stay away from that autoparts store for advice. Also venting refirgerant into the atmosphere purposefully is punishable by a very hefty fine.

Okay here's the newest that's right it is a wiring problem bc I took it to a guy today and only one of the parts where my ac relay goes is hot rather then two. When we put a paper clip on the hot and a ground the compressor kicks on and my ac blows cold. So my compressor isn't broken. Now where do I start looking for wires? Behind that compressor like you said?
What did he jump? Sounds like a faulty High/Low pressure switch to me. If your not in anyway, shape or form familiar with AC do not work on it. I would highly suggest taking it to a shop or take a class and familiarize yourself with it. AC is stupid simple once you understand what everything does:thumbsup:
 

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Discussion Starter · #8 ·
okay heres what i've got now. I've started learning about my AC and whats going on is that there is now power to my high/low plug. Now correct me if im wrong but its the two green wire plug behing the compressor right? if thats right then when i have my AC on should that be getting power? because if so i turned it all on and checked the plug with a test light and it didn't have any power... it also doesn't have any power at the relay. I only have one hot when i unplug my relay and test light the four holes... there should be two hot and two negative right? one for the compressor and one for the high/low?
 

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mine was a $150 gasket mine was doing the same thing but now my compresser is out now
 

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Bringing up an old thread.......

My a/c setup is sketchy as installed by PO. It consists of no relay in the fuse box and a switch in the cab that you have to flip if you want the a/c to turn on, in addition to having the dash a/c switch on. I tried undoing that and replacing the relay, but the a/c never got cold whereas it does get cold with this rigged switch thingy. I'll admit I am clueless about a/c, but it sounds as if it could be some sort of high/low pressure switch???
Can anyone help clue me in on this?
 

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Anybody ever hear of this before? What is being passed by with tapping right into the relay with only two wires? Someone on here knows whats going on. Not me......
 

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When I disabled the switch and replaced the relay, the ac was not cold at all.
 

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Bad wire that got shortcut to make ac cold?
 
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