Question about 1999 Jeep Grand Cherokee

1 Answer

A/C compressor turns on and off even though A/C is switched off

Jeep Cherokee 4.0 year 1999 A/C compressor clutch cuts in and shuts off about every 30 seconds even with the A/C switch in off position. When A/C ist turned ON everthing works fine.

Posted by on

  • akobaer May 20, 2009

    Thank you. I will check the switches and PCM.

×

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 1,623 Answers

Hello akaobaer...Sounds like you have a pressure switch defective or the system charge (freon) is low...The a/c clutch relay is operated by the Powertrain Control Module. However there are inputs from the low pressure switch (located on the accumulator) and a high pressure cut out switch (located on the discharge line near the compressor) that control whether or not the PCM turns on the clutch relay as well.
If the refrigerant level is low, the PCM low PSI switch will cause the clutch to cycle.
The PCM turns on the relay by grounding the negative side of the relay coil...The low PSI switch should turn on (close) at approx 34 PSI.....and will turn off (open) at 20-22 PSI...May sound complicated but it's really not. Have a qualified HVAC tech. check the system for leaks before recharging it, if needed.
Good luck...i hope this answers your question and will fixya up...

Posted on May 19, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

Hi my name is leo and I have a 2002 jeep Cherokee Laredo a/c clutch will engage


Faulty low pressure switch , Google it to see how to replace, or you an unlucky it and run a jumper wire between the terminals/ But beware- bypassing the low pressure switch can ruin the compressor if it gets low on freon.

Jan 25, 2015 | 2000 Jeep Grand Cherokee

1 Answer

How do i fix 1999 jeep grand cherokee cruise control


Test and make sure brack switch and lights are ok.
make sure throttle position sensor and speedometer is ok.
check electricat connector and vacuum lines are good and connected at cruise servo.
make sure fuse is good.
check clutch switch.
if all above good replace servo.

Jul 12, 2014 | 1999 Jeep Grand Cherokee

1 Answer

I had auto shop put freon in and then they said was working fine...said pay and you can go, car cooling just fine...I go out to my car and complete system is dead. The fan controls in dash now dead....


If your system its empty of free on, yow wont be able to activate your ac compressor, you might have a leak some where, this its the simple answer, there could be more problems, a bad blower motor, relays, fuses, cloged system, etc.:)

Sep 17, 2012 | 1999 Jeep Cherokee

1 Answer

AC not running in my 1998 Jeep Cherokee. Changed AC clutch compressor RELAY, freon level is good, temperature sending unit replaced along with cooling fan! Checked all fuses still good. Can't seem to...


Hello, You have two switches which work off the pressure of the Freon. Both of these switches cut off the power to the compressor. One is for HIGH pressure and the other is for LOW pressure. Check for power at the compressor clutch connector harness while the controls are set and the engine is running. You may have power and a bad clutch.

When you say that the Freon pressure is good, does that mean the pressure is within the proper range? Too much Freon will make the HIGH switch cut off power and too little will make the LOW pressure switch cut off power.

The ideal amount(ozs) of Freon is what is recommended by the Manufactuer and it will provide a moderate amount of pressure of about 35psi-40psi. You can borrow pressure gauges, called Manifold gauges to measure your system at autoparts stores with loaner programs.

The low pressure side of the system is the one you use to induce the Freon to go into an empty system. You can bypass this switch by taking off the connector and putting a "U" shaped jumper into the harness and the compressor clutch should get power to LOCK up all of the time.

You can take off the switch connector at the compressor clutch and then check for power when bypassing the HIGH pressure switch if the LOW pressure switch does not make the system get power. Only, really only bypass the HIGH pressure switch with the clutch connector disconnected. The HIGH switch is there to prevent damage to all of the components from seals to lines to every piece of Freon hardware in the car. Bypassing with the A/C clutch disconnected will allow you to know if power is getting to the compressor clutch.

Finally, you can get FREE wiring and fusebox diagrams through Autozone.com. Just sign and register to their site and then you can print the documents for yourself.

Good luck with this repair and I hope my solution helps you.

Mar 19, 2012 | 1998 Jeep Cherokee

1 Answer

1993 Grand Cherokee won't stay running or turn over


Sounds like a clogged fuel filter to me, maybe look into the TPS: throttle positioning sensor. Good luck

Feb 11, 2012 | 1993 Jeep Grand Cherokee

1 Answer

1999 Jeep Grand Cherokee. AC problem. Fan and inside controls have power but compressor clutch not engaging. I am thinking that there may be a relay that is out. Any suggestions for troubleshooting...


The compressor clutch won't engage unless there is freon in the system. Connecting a gauge to the low pressure port should tell you if there is. Pressure in a system that isn't running varies with the outside temperature.

Apr 16, 2011 | 1999 Jeep Grand Cherokee

1 Answer

The clutch on the ac compressor of my '96 Jeep grand cherokee engages for about 5-10 seconds then disengages for another 5-10 secs. Any idea on what causes this?


Have your freon pressure checked out, more then likely low on freon, low pressure switch will cut a/c compr off, when not enough freon pressure, or it will damage the compr.

Jun 30, 2010 | Cars & Trucks

1 Answer

1999 Jeep cherokee Sport...turn signals don't always work


Sounds like a broken directional switch inside the column. You have an airbag system. I strongly recommend you either get yourself a chiltons or haynes manual and follow dis assembly instructions EXACTLY or have a shop do the work for you. If airbag deploys while you are working on it it can and wll ruin your day in a big hurry. (trip to hospital)

Dec 30, 2009 | 1999 Jeep Cherokee

1 Answer

A/C problem with 99 Jeep GC Laredo


If the compressor is running and the lines are getting cold that leaves the evaorator having a block, don't recall if that year has the orifice tube or not. In any case it is going to require opening the systems cleaning the lines and the oriffice then refilling the system. That means a vacuum pump and refriedgerant oil and the associated guages and freon. Live on the Gulf coast and you are right we do get hot down here!

Aug 31, 2009 | 1999 Jeep Grand Cherokee

Not finding what you are looking for?
1999 Jeep Grand Cherokee Logo

714 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jeep Experts

yadayada
yadayada

Level 3 Expert

75817 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Kevin Daniels

Level 3 Expert

1455 Answers

Are you a Jeep Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...