DIY AC Re-charge

[phatphuck]

AC Compressor is not wanting to run consistently while attempting to fill. It cycles a couple seconds on and off.

I understand it needs to run continuously while taking in new refrigerant.

What is the recommended method for keeping the compressor running long enough to take on a charge?

 

[Supercharged111]

Shove more freon down its throat. Are you monitoring low and high side pressures and discharge temps? My 1500 leaked down over the winter and it did the same as yours with just 1 bottle. As I got more into it, it cycled longer and the temps came down.

 

[BNielsen]

I used a paperclip and jumpered the the connector at the accumulator, it worked although that was when my AC Compressor was on the fritz due to a wiring issue,
I don't think a properly cycling compressor would have a problem going that route but I'm not 100% certain.

 

[phatphuck]

Shove more freon down its throat. Are you monitoring low and high side pressures and discharge temps? My 1500 leaked down over the winter and it did the same as yours with just 1 bottle. As I got more into it, it cycled longer and the temps came down.

Not monitoring hi and low. Although I was watching discharge temp.

Low side pressure just kept going up as I was feeding it, would drop when the compressor kicked on then back up as it stopped.

When you say keep filling, do you mean pulse as the compressor comes on and let off when it shuts off or what?

I used a paperclip and jumpered the the connector at the accumulator, it worked although that was when my AC Compressor was on the fritz due to a wiring issue,
I don't think a properly cycling compressor would have a problem going that route but I'm not 100% certain.

This was with the truck running and ac on high right? So you just jumped it until the compressor was running by itself?

 

[PlayingWithTBI]

The cycling switch will open when your pressure is below ~25PSI. Just turn it on and rotate the can upside down and right side up until you get around 2 cans in it. Getting the 3rd can in may require you raising the idle some. You really should have a set of manifold gauges when charging the system since you don't know how high your pressures are. If there's a clog or restriction in the high side you may be building too much pressure. My 88 didn't have a high pressure shut off switch (88 & 89 didn't come with one), when I shut off the engine on a hot day, restarted it 10 minutes later the pressure went so high, it blew the pressure switch out of the back of the compressor - sounded like a shot gun going off! After buying a new compressor I wired a high pressure switch (on at 250, off at 330PSI) in series with the cycling switch. No problems anymore.

Anyway, you're running a risk of blowing out your system if you don't know your pressures on both sides.

 

[HotrodZ06]

Definately use manifold guages, I won't touch an A/C system without them. Saves alot of headaches and possibly other injuries. Saw one guy have a hose blow and left a really nasty bruise because he didn't know his high side pressure

 

[phatphuck]

Definately use manifold guages, I won't touch an A/C system without them. Saves alot of headaches and possibly other injuries. Saw one guy have a hose blow and left a really nasty bruise because he didn't know his high side pressure

Anyone know the hi and low pressure should be off the top of their head?

Think I can get a set of gauges from harbor freight for not too expensive. They should be adequate for how infrequently I do AC work

 

[Supercharged111]

They'll do fine. Just give the pressures a Google, there are a million charts out there. I always have a bucket of hot water to keep the freon can in as it gets really cold while it drops in pressure which makes it take FOREVER to get it into the system. Dumping the can upside down can blow a compressor. I've done it before and not hurt anything, but it's not a good practice.

 

[PlayingWithTBI]

Dumping the can upside down can blow a compressor.

Yes, I guess I should have expounded on that a little further, my bad. The reason I said rotate the can back and forth is to keep from slugging the compressor, you can watch the low side (Blue) gauge and when it starts going up rotate it back closer towards vertical. You can go back and forth to maintain a slightly higher pressure to get more Freon in AND not get too high of a pressure surge. But, again you need gauges.

 

[Kran]

compressor is cycling on/off every few seconds because it doesnt have enough freon. keep filling it. this is assuming all the pressure switches are working properly