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Anonymous Posted on Sep 09, 2014

How much low side pressure must you have to engage clutch on compresser?

Low side is low when motor running

1 Answer

radracer2861

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  • Posted on Sep 09, 2014
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Usually around 30 low side running with compressor on, will usually go around 100 plus without engine running , you can jump terminals on the low pressure switch on the accumulator , but if you have any negative pressure reading like if it pulls into a vaccum on compressor start up , then you have a orfice tube blockage and high side will go around 3 to 500deg

5 Related Answers

Anonymous

  • 6982 Answers
  • Posted on May 23, 2009

SOURCE: trying to recharge but reading in red on canister port (low side?)

Likely you have a valving problem or obstruction within the system. To do any real a/c work, you need a Set of gauges so you can monitor both high and low side pressures. Additionally you need an evacuation pump in order to remove any air and moisture in there, neither of which are good. You also need some experience doing this kind of work. Third, I have recently spoken to an a/c guy I know and he told me that the sealers they put in many of those cans will gum up and destroy the expensive machine used by most shops that do this kind of work...making me wonder what it does to the car's system itself??? A short burst of freon without sealers or dyes is OK to add to a system that is just a little warmer than it should be, but otherwise either get the correct tools and some training, or leave this work to the pros.

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Anonymous

  • 1 Answer
  • Posted on Aug 18, 2009

SOURCE: 1992 gmc c1500 ac compressor relay location

I pulled this from another web site
"The AC clutch relay is located inside the cab on a metal bracket that is easiest to see when you remove the glove box compartment.

The relay is on a metal bracket bolted to the top of the plastic air box, forward and to the center of the dash from glove box.

There are three relays in a row on that bracket. The AC clutch relay is the end one closest to the driver’s side."

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Ray Keckeisen

  • 599 Answers
  • Posted on Nov 12, 2009

SOURCE: low oil pressure

did you check this with a mechanical guage,what weight oil are you using,does this car have an oil cooler. get back to me, also what engine and milage Thanks Ray

Anonymous

  • 59 Answers
  • Posted on Mar 01, 2010

SOURCE: low oil pressure 93 GMC P/U w/350 motor w/205,000 miles gauge

While engine is running, open the cover where you add oil to engine and see if you see a good flow of oil, if good flow, could be as easy as replacing oil sending sensor. got to realize that if poor maintenance history your engine may not be building enough pressure at iddle to move your hydraulic operated valves, only when you rev it up it will pump enough to run smooth. if running engine too long, you may cause more damage to other engine components such as crankshaft and cam shaft bearings. if you can spare a few bucks, have a good mechanic check your oil pressure with a mechanical gauge. another cheap option is to replace oil pump. last resort if you love your truck as much as we do,replace engine or rebuild it. At 205,000 this is a normal symptom, other than timing chain problems, most engines don't make it that far. hope this helps!

alicantecoli

Colin Stickland

  • 22516 Answers
  • Posted on Jun 07, 2011

SOURCE: clutch on comp will not engage tried jumping

if the Ac compressor clutch isnt engaging even with a hot wire then the solonoid has packed up if does engage then it could be a pressure safety switch although i would empty the system with my machine and weight the gas i take out as if less than 150 grms then it will not work ,never mind the pressure its the weight of gas in the system that makes the switch allow the compressor come on

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0helpful
1answer

The aircon system is fully gased yet the compresser wont engage, are there pressure switches in the system

Yes , two , a low pressure an a high pressure cut off switch . If either of these were bad there would be a DTC - diagnostic trouble code stored in the PCM - engine computer . Does your Captive have manual or automatic heating an A/C ?
Pressure transducer switching incorporates the functions of the high-pressure and the low-pressure cutout switches along with the fan cycling switch. The pressure transducer is located in the high-side liquid refrigerant line behind the right strut tower, between the right strut tower and the front of dash. The output from this pressure transducer goes to the electronic control module (ECM), which controls the compressor function based on the pressure signal.
HVAC Compressor Clutch Does Not Engage

1

Did you perform the Diagnostic System Check - Vehicle?
Go to Step 2
Go to Diagnostic System Check - Vehicle

2

  1. Start the engine.
  2. Turn the blower switch to any position except OFF.
  3. Press the A/C switch to the ON position.
Does the A/C compressor clutch engage?
Go to Testing for Intermittent Conditions and Poor Connections
Go to Step 3

3

  1. Connect a scan tool.
  2. Use the scan tool to command the A/C compressor clutch relay ON. When the relay is energized the cooling fan will also run at low speed.
Does the A/C compressor clutch engage?
Go to Step 8
Go to Step 4
1helpful
1answer

1998 dodge ram1500 airconditioner clutch not getting power

You may just be low on refrigerant, if the system is low the compressor will not engage, the oil that lubricates the system is carried by the refrigerant as it is pump around the system, so if it is low the compressor will seize up, so it is shut off by the low pressure sensor switch. To confirm this is the problem have a shop that repairs AC systems run a pressure test on the system with a set of AC pressure gauges. If it is low you have a leak, it must be repaired before it is re charged.
0helpful
1answer

Ac compressor clutch will not engage on my 98 yukon.

The most common cause of no clutch engagement is a low state of refrigerant charge in the system. Have a set of AC pressure gauges hooked up and bypass the compressor cycling switch and check the pressure on the low side charging port, you show shop 28-32 PSI at idle.
11helpful
1answer

Compressor isnt turning at all dont know if i need new one or if i need new clutch how can i tell

The pulley on the compressor is always running when your engine is running, but the only time
it compresses the freon is when the clutch engages, if the compressor's pulley was not turning,
it would have already snapped a fan belt or your serpentine belt. voltage runs from your fuse box
thru your air condition switch on your dashboard to a low pressure switch that is located at the
accumulator a long cylinder,close to the firewall under the hood or close to the condensor, front
of the car. the switch detects freon pressure in the accumulator, if there is freon pressure, the switch
will stay closed and allow voltage to go to the compressor clutch to engage it and compress the freon,
if there is no freon pressure the switch will open, and there will be no voltage to air compressor, its a
saftey switch to keep your compressor from getting damaged.its possible that the switch could be bad
it may not have voltage at the switch, or it may be open because there is insufficient freon pressure.
check and make sure there is freon in the system.check for voltage at the low pressure switch if you have freon in your system and voltage at the pressure switch, set your ac on high, pull the molex off
the switch, and jump it out with a jumper wire, if the clutch engages and your car starts to cool, just
replace the switch. if the clutch engages but does not cool, then your ac system has some blockage
in the lines. if the clutch does not engage at all then it would be the compressor clutch. good luck!
0helpful
1answer

Need to fill air where is low pressure intake

The a/c has a low pressure port on the low pressure side of the a/c piping system.

One can identify the low side by looking at the 'thicker' pipes vs. the 'thinner' pipes on the high pressure side.

There may be a canister that has a low pressure port on it on the passenger side. Or else, it's on the thicker piping itself.

There may be a blue or black cap on the port.

The pressure should read 35psi to 45 psi on the low side when the a/c clutch is spinning or engaged.

When the a/c clutch is not spinning or engaged then the pressure should read 75 psi to 100 psi on a hot day.

4helpful
3answers

A/c not blowing cold air

80lbs on the low side is WAY too much if the clutch is running, the high side you should see 125-150ish, the low 30-40. I would feel the lines (the bigger line going into the firewall to see if it is cold when your pressure is right) if so suspect a blend door motor which controls the hot and cold switching inside.
0helpful
1answer

2003 suzuki sx awd. during hot days 22 celsius, turn on a/c and loud rattling noise starts when car is at standstill at traffic lights. no rattling when on the move with a/c on. any good diagnostics will...

This hjas a possible two part problem, the first part is the a/c compressor has a clutch on the end of the shaft and is engaged with the a/c compressor switch turned on, which means while the car is running, you turn on the a/c and walla, you get cold air(as long as it is fully charged), the belt drives this clutch which in turn spins the inside of the compressor and starts to mechanically **** freon into it through means of the low(suction) side, the larger diameter port, once low pressure freon either 134a for everything built after 1994 or freon r12 for cars built before 1994 enters the compressor it is then compressed into a high pressure liquid which has a high pressure test port that is always smaller in diameter then the low side (fill) port.
When the clutch is engaged, it will only slightly rattle after it gets a few thousand miles on it however as the vehicle gets more useage and the a/c gets more useage(considered extreme condition useage) more use then normal vehicles would otherwise get, the clutch starts to wear out causing this rattle. A clutch head puller is used to remove the clutch can't do it without the proper tools, the belt must come off before doing the replacement.
Any parts store will have the tools and the clutch, you don't have to release any freon for this repair.
Another reason for a rattle could be the a/c system is low on freon and oil.
Buy a freon charge kit with a one pound can of 134a freon + oil combo and with the car running and a/c on high blow full cold attach the charge hose and freon into the low side port, rattle should cease soon as the vehicle reaches is full charge, should't take more then 2 pounds(cans) of freon, system hold 2 3/4 pounds empty each can is one pound.
Happy Motoring!!
2helpful
2answers

Had to have engine replaced on 2000 dodge stratus, now a/c clutch does not engage. all connections appear to be connected and fuse is good

You may be low on refrigerant (R-134a) if the a/c system does not have enough it will not engage the clutch until a pressure switch has been satisfied. You have 2 pressure switches a High side which tells the compressor when to shut off, and a low side telling it when to come on. Also if the pump runs all the time and does not cycle on and off then the refrigerant would be low. good luck
1helpful
1answer

The air conditioning blows only hot air

Is that your static pressure readings??? If that is your static pressure readings that's good. When the engine running and fan on high and a/c compressor clutch engaged you should have 25 to 35psi on your low side and 200 to 350psi on your high side. If the clutch is engaged and that is your readings, replace your a/c compressor. Keep me posted, be glad to help.
Jun 29, 2009 • 2003 BMW Z4
2helpful
2answers

A/C compressor clutch won't engage, system won't cool

Sounds to me like its simply ran out of gas!, get the system inspected, the clutch wont engage if there is no pressure in the system, hence the switch problem.
Get it recharged and check for leaks, vehicle with air con will loose around 50grams per year from normal usage, if its been years since it was check it could simply just need recharging.
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