A/C compressor won't kick on

[razrback]

OK ole great ones of the board, need help to begin search. Compressor will not kick on unless I add freon. When it's running numbers look good and cold air at the vent. However when I disconnect gauges, turn off engine, it won't come back on

So, where do I start this journey?

 

[stamp11127]

Sounds like you have a pretty good leak. Check the service ports for leaks as a first start.

 

[johnboneske]

I agree with it leaking a lot!

 

[1955moose]

Leak, have a shop if you can't pressurize system through as Stamp stated ports It's got to be 100 percent air tight, before adding freon.

Sent from my N9131 using Tapatalk

 

[razrback]

Thank you all for your replies. I've been out of town and just now getting back to the car.

It may have just been a coincidence that the compressor kicked on when i was adding the freon, not sure. Today, after sitting the w/e the compressor kicked on for about 2 secs, went off, came back on a few seconds later and ran for at least 30 seconds, went off and stayed off.

I hooked up the gauges and the static readings were the same on both sides and matched the 88 air temp. I hooked up another can of freon to test the theory above and nothing. After a few minutes it kicked on, low side never went below 50 and high side was around 200. I never saw any freon going thru the glass on the gauge and the can was sitting upright.

So what all has to happen to make the compressor kick on? Is there a way for me to do that manually or does the above info point to the problem or do I really want to manually run at this point?

I replaced all the A/C parts under the hood about 4 years ago and it's been perfect until now.

 

[johnboneske]

Can sitting upright is charging gas, you always want to charge with the can upside down so.it liquid, well on the low side anyways...

What year is your Expedition?

 

[stamp11127]

When you are adding the refrigerant, do you purge the air in the hose prior to charging the system? If not, you have some air in the system.

The low side pressure switch needs to be powered, closed plus a good ground is needed.

When you changed parts in the past did you add any oil? If so how much?

We are starting a new ac class at the school in 2 weeks. The problem you are having we would instruct the students to recover the system and recharge back to factory specs. Then proceed with any needed repairs based on the pressure readings.

 

[razrback]

I don't remember the exact amount of PAG oil, but I used the amount listed on some Ford website for the vehicle. It's possible there is air in there somewhere, I try to vent before filling, but whether or not I'm doing it correctly I don't know.

I'm just about where you are, too many variables in play right now so I'll take it in and have it recovered and recharged and see what happens. I'll update you guys.