I just signed up for this forum because I'm beating my head against the wall on my AC I had to replace my AC compressor about 5 months ago during the winter I did it when I had money. Hi then went ahead and pumped a can of 134 into the high side and the AC was working fine then my blower motor resistor went out and I only had number 4 on my fan working so I replaced that and now my one two three and four is working but my AC clutch is not engaging anymore. I used a gauge and check the high side and I was over pressured so I started bleeding the air down but it still won't come on I feel like I found the low pressure switch which is right by the radiator but it has 4 wires connecting to its I don't know how to jump it to see if the AC will turn on anybody that can help please let me know it's a 99 degrees in Colorado today

 

First things first, it sounds like you refilled improperly. It should have been taken to a shop (unless you do hvac for a living and have a vacuum pump and a set of gauges) and been pulled into vacuum prior to introducing refrigerant. Two reasons why - pulling into vacuum and closing off the manifold valves, then observing the gauge will verify that the system is sealed. Second is that even traces of atmospheric moisture (which exists everywhere on planet Earth), when it contaminates refrigerant, causes said refrigerant to become corrosive. Vacuum will ensure removal of any moisture.

I would start with pulling the two wire connector at the compressor and test for 12V. If no voltage then you need to find out why. If there is voltage yet the clutch does not engage then likely issue with the clutch coil.

 

Thank you for the reply I'll definitely remember that for next time my dad like you just throw a can in it and you should be good which I was for a minute if I don't have 12 volts do you have any where I should start looking I will check tonight when I get off work
thank you again for your reply

 

Working on AC is more than just parts swapping. What made you swap it in the first place?

As Z28KLR mentioned you need guages and vacuum pump as well as an understanding of how all the parts work together..

You should have replace the receiver drier and orifice tube. They are just parts you change whenever you open the AC system. The receiver drier will scavenge any moisture that may be left in the system even after vacuuming. The orifice tube is the component that separates your high and low side and has a very fine mesh screen that can easily get clogged. It's a preventative thing to replace it.

Also, I hope you mean you added refrigerant to the LOW side of the system, not the high side? Considering the fittings are different sizes and that freon mfgs use only the low side fitting for their hoses, I'm going to assume you had a typo

One 12oz can of freon will not recharge most of the automotive systems out there and defintely not on a mustang. they generally take 1.2 lbs or more.

There was oil in the compressor when you put the new one in.

Did you bother to measure (in ounces) what was in it from the manufacturer vs what ford states is appropriate? Some Compressor manufacturers put the entire amount of PAG oil into the compressor assuming you are flushing the system which removes all oil and contaminantes from the entire AC system.. Some manufacturers only put what Ford specifies what should be in the compressor, assuming you aren't flushing the system.

If they put all of the oil of the entire system in the compressor and you didn't have a leak, you are probably overfilled on your oil which could reduce cooling efficiency and may even mimic a bad compressor.

If you had a leak and the manufacturer only put in what supposed to go in the compressor, you're low on oil and can fry your compressor.

You never know what the mfg did for your compressor unless you actually measured what was in the new one to begin with and refilled it with the proper amount.

Do yourself a favor before you start just adding Freon, get yourself a set of manifold gauges and see what's actually going on.

 

Ok well it deffently sound more than part swapping I found a guy that say 40$ diagnostic and 180 for full vacuum and recharge what you think of that price? He kinda just said same thing you said hopefully he honest cause don't seem like it's something I'm able to do. Thanks for the replys.

 

The cost is not unreasonable. Most places charge between $35 and $50 to hookup the gauges for diagnostics, and charge 125-150 for an evacuation, vacuum, and refill. The way it works is when they evacuate your system, they put the Freon from your system into a holding/recycling tank that weighs the amount of Freon in ounces.

When they go to refill your system after the vacuum, they will put in the exact quantity of Freon your system had in it when you brought it in, plus whatever amount more you need to have it at the proper level. That's where they charge you for the Freon by the ounce. That cost is above the evac, vac, refill cost and can easily make it $150 to $180.

But, if your guy says freon is included for the $180 that's pretty fair. The only other thing you should ask him is what kind of warranty is he providing? While he didn't replace anything, he is checking for leaks which means he should at least be able to give you a warranty for no leaks for X number of months.

 

Check the "Compressor Clutch Relay".......mine was acting weird and the relay was the problem!!

Good Luck!!