a/c compressor pressure switch

[whitetrash]

im thinking this is my issue on my truck. does anyone know if i have to drain the system to remove this?

edit: i am referring to the switch that is located on the rear of the compressor to be specific

[stephen4785]

im thinking this is my issue on my truck. does anyone know if i have to drain the system to remove this?

edit: i am referring to the switch that is located on the rear of the compressor to be specific

If it's the high pressure cut out thats held in with a c clip then yes you have to evac the system.
Does it look like this?

[ram57ta]

If you know the rest of the system is ok and you have good pressure readings using gauges...and this switch is defective...I would say bypass it unless you just want to evac and recharge the system.

[whitetrash]

Yes that's it. I'm fairly certain that its the switch. The a/c works great for awhile then cuts off after about 5 miles. I just replaced a bad valve and refilled the system so I know it's full.

[Captain Crawfish]

id go ahead and do it right. evac the system replace it. its a safety for the compressor so yes it needs to work bypassing it isnt a good idea. remember an ac system has to be charged with the correct amount if its not it will cause the low and high pressure switches to interrupt the compressor. verify your low and high psi readings at idle.

[whitetrash]

id go ahead and do it right. evac the system replace it. its a safety for the compressor so yes it needs to work bypassing it isnt a good idea. remember an ac system has to be charged with the correct amount if its not it will cause the low and high pressure switches to interrupt the compressor. verify your low and high psi readings at idle.

Yeah I'm not gonna bypass it. It's a cheap part and I think I know someone with a vacuum machine for a/c I can use.

I have gauges but no R134 quick connect couplers. Anyone know where I can grab some in the n ft worth Keller area

[stephen4785]

Yeah I'm not gonna bypass it. It's a cheap part and I think I know someone with a vacuum machine for a/c I can use.

I have gauges but no R134 quick connect couplers. Anyone know where I can grab some in the n ft worth Keller area

Just the ends? Sounds like you have R12/R22 gauges? Good luck finding some today. Only local sources Iv ever found is Chandlers automotive or a tool truck.
Does the compressor stop cycling after 5 min or doe it just stop cooling? You need to hook up some gauges and watch the pressures when it stops cooling or cycles off. If the high pressure cut out is kicking off then I'd check and make sure the fan clutch is working or electric fans are coming on. You really need to know what the pressures are doing. There's a multitude of things that will casue your symptoms but a faulty high pressure cut out isnt one of them. The only reason Iv ever replaced one is because they started leaking freon through the pins on the connector or around the metal part thats crimped over to hold in the plastic part.
The high side switch should have power groing through it at all times and when the pressure gets too high it will open and break the signal to the ecm. The switch is a normally closed switch.

[00pooterSS]

Rent gauges from Autozone, watch the pressures and let us know.

[Blackpony]

Oreilly and autozone both rent gauges

[whitetrash]

Rent gauges from Autozone, watch the pressures and let us know.

Will get some tonight or tomorrow

[00pooterSS]

Is this on the 00 Z71 in your signature? If so, make sure the fan clutch is good. At idle the fan should be blowing a good amount of air. My truck was acting similar and I have seen others do it when the clutch goes bad.

The way I generally do a quick check on them is dangerous but it works, you can take a shirt or rag and ball it up real tight and lightly touch it to the blades as they spin, you should NOT be able to easily stop the blades. If you can, change the fan clutch. If you do this be careful and leave lots of room around your arm to yank your hand back if need be. I don't like recommending this but it works.

Also if the fan isn't doing it's job, the high side pressure will be really high (over 300 psi, can go over 400 if it's pretty hot out, and that's assuming it is charged properly).

Look through the grill and make sure the condenser isn't clogged with dirt etc.. If it is, pull your fan shroud and take a water hose and blow water through the radiator out front ward toward the grill (you should do this for good measure regardless actually)

[stephen4785]

The way I generally do a quick check on them is dangerous but it works, you can take a shirt or rag and ball it up real tight and lightly touch it to the blades as they spin, you should NOT be able to easily stop the blades. )

I roll up a newspaper or magazine.

[whitetrash]

Is this on the 00 Z71 in your signature? If so, make sure the fan clutch is good. At idle the fan should be blowing a good amount of air. My truck was acting similar and I have seen others do it when the clutch goes bad.

The way I generally do a quick check on them is dangerous but it works, you can take a shirt or rag and ball it up real tight and lightly touch it to the blades as they spin, you should NOT be able to easily stop the blades. If you can, change the fan clutch. If you do this be careful and leave lots of room around your arm to yank your hand back if need be. I don't like recommending this but it works.

Also if the fan isn't doing it's job, the high side pressure will be really high (over 300 psi, can go over 400 if it's pretty hot out, and that's assuming it is charged properly).

Look through the grill and make sure the condenser isn't clogged with dirt etc.. If it is, pull your fan shroud and take a water hose and blow water through the radiator out front ward toward the grill (you should do this for good measure regardless actually)

Condenser is clean and I swapped to electric fans. They are working as well

[00pooterSS]

Condenser is clean and I swapped to electric fans. They are working as well

I switched mine to electric also, I did all the OEM 07+ stuff including pinning the computer and programming it to control the fans.

What setup did you use for your electric fans?

[00pooterSS]

I roll up a newspaper or magazine.

I like the magazine idea, just never had many handy around the shop, fatboy always had them in the bathroom with him. But there were always rags.