I replaced the a/c compressor on our 2003 T&C recently. It was a new comp. not a reman. I also replaced the dryer and expansion valve with new o-rings. R134a system of course.

This was due a locked up clutch on the factor original comp with close to 180k miles. The compressor itself did not fail just the clutch. The oil that came out of the original compressor was as clear as brand new oil with no visible contaminants. I cost of a clutch alone was close to the cost of a reman compressor so I decided to go that route (long story after that but company took 3 weeks and 3 promises to send out my reman compressor so after calling to complain AGAIN and ask for a refund, they sent me a brand new comp. for the same cost since they could never get my reman in stock.)

Anyway.... it's been a few weeks since it was installed and I had to drive the van but the compressor was full of factory oil and I never attempted to even engage the compressor until I could get the system vacuumed.

Last night I have vacuumed down to 29 microns (or what the measurement is called), turned pump off and even after over night the vacuum held according to the manifold gauges. So I attempted to put in the first can of R134a (using synthetic Arctic Freeze). Because of the vacuum, I could hear a suction for a moment and could tell a small amount of coolant went in (low side), but with engine running and a/c button engaged, the compressor never started cycling to pull the rest in.

So more research, I see this is fairly normally since the system was vacuumed and had no coolant at all left in the system. I've read suggestions to try and put in a can upside down on the high side as they do in the factory to get enough in the system so the low pressure cut off would allow the clutch to start cycling.

Another option is to jump the low pressure cut off to force the clutch to engage.

Well, I don't have the right hose nor know how to force a can in liquid state in the high side so I have attempted to jump the low pressure cut off switch.

I'm running into conflicting information. Some sites say that these vans don't have low pressure switches and you have to jump the a/c relay on the power distribution box. Some sites say that the switch next to the dryer is indeed a low pressure cut off and to jump it.

Apparently I'm not jumping something correctly as I can't force the clutch to engage.

Can someone offer insight as to what wires or terminals exactly to jump to force the clutch to engage?

If jumping the a/c relay do you leave the relay in place (slightly raised to access the prongs) or pull it? I've read to jump point 30 and 87a but 87a makes no connection on the box.

Frustrated and hot.

 

And what did they suggest you do when the compressor engages, and all 200+ pounds of head prssure Knocks that can into your SKULL?????

No joke,,,,That can will rupture and you will be frostbitten and Blind....
30 and 87

 

I apologize. I should have given the full instructions, I just thought after reading that at several places that it was something common. The instructions did say to leave a/c turned off so it doesn't engage if doing that. But I won't be attempting that in either case.

30 and 87[/quote]

Do you jump those with the relay completely out/off, or do jump those with the relay inserted?

 

No need to apologize.....It IS common practice at the factory, but with the specialized equipment. Pro equipment installs the freon by means of weight...Not pressure, so I can charge Hi, or low or both...But NEVER with the car running.

I would NEVER discourage anyone from doing their own work, but this area is NOT the project for the Do it your self Crowd. Maybe moneey is tight, maybe you need the thrill of satisfaction that comes with a JOB COMPLETED,..But the reality is...You cant put a price tag on Your eyesight.... MAybe I'm oversensitive to the issue but Ive seen first hand, when those cans rupture....To a guy that I worked next to for years, and he will never see his sons baseball games, or his daughter get married, or the smile on his grandchilds face., and I cant believe that was all worth a COOL BREEZE in a CAR...Just Think about that....

Now...Pull the relay out completely

_
87
85 l l 86

30
l

 

Aww DAmn..... My artwork didnt work out at all.....

Try This Instead..... Relay Terminals

 

Thank you.

I pulled the relay, inserted a jumper wire between where 30 and 87 would be if the relay was inserted.

Started engine, turned on a/c...... clutch not engaging

I wish I hadn't done it, but due to forced circumstances, I had to start using the van as soon the compressor and other components were installed without charging it. But as originally mentioned, the a/c was never attempted to be used nor the defrost (which temps were high enough that hadn't been needed anyway). In addition, the low pressure should have kept from attempting to engage. Could this have damaged the compressor? Wouldn't the clutch still click or do something or cause a drag on the system anyway?

I hope it's just another relay/switch or loose power connection somewhere.

More hand holding please as to what to look at next

 

if u jumped the relay and it did not turn on then either u did not plug the compressor back in or u broke a wire some where. or blew a fuse

 

I can't find my meter, so using a simple test light....

15a a/c fuse under the hood is good.

I get power to pins 30 and 85 when the key is on.

I unplugged the 2 wire harness connection from the compressor and checked each wire, while jumping the relay (pin 30 and 87) with key just to ON, engine not running, no power to either wire going to the compressor.

left jumper in place, started engine, pressed a/c button, still getting power to pins 30 and 85 (and also 87 now of course since it's jumpered.... still power at a/c fuse. no power at either wire going to compressor.

so i lose power somewhere from the a/c relay to the 2 wire compressor connector.

I don't see any place where a wire could have gotten broke while replacing the compressor. but power to the compressor did work before replacing it.

what else should I check?

what colors are the two wires inside the harness for the compressor? do the same two colors stay the same from the power center to the plug?

 

Well, it's fixed. compressor is running. dumb cause, almost too embarrassed to say what it was.

The power connection to the compressor. I had already pressed it together to ensure it was seated firmly, but unplugging it to do some tests and then plugging it back up, for what ever reason, made it work now. I hope it just wasn't seated properly and not a loose connection that is only working for now. But at least I know where to look if it stops again.

And I know where to look at FIRST, next time I'm in a similar situation

Thank you all for your help. It really did help.