Mechanics

COMRESSOR CLUTCH WILL NOT ENGAGE

1997 Chrysler Sebring

Air Conditioning problem
1997 Chrysler Sebring 6 cyl Front Wheel Drive Automatic 141000 miles

The air conditioning compressor clutch will not engage. The system is properly charged, the high-low switch has been replaced, the relay is good. The compressor clutch will engage when the ground side of the relay coil is bypassed, and then, the system does cool. According to the wiring diagragm, the ecm is connected to the AC control circuit. What part does it play, and are there any other switches or sensors in the system that I may have overlooked? Thank you in advance.
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Smipple2
April 23, 2009.



Ok do you have a digital mutli meter? If not you will need one as there is a couple of test I would like to walk you through. Get back to me and thanks.

Racefan966
Apr 23, 2009.
Yes, I have both digital and analog multimeters. Also the ign. Codes that come up are 12, 23, & 33, one of which has to to with an open AC clutch circuit, and the code reader codes are p0112 & p1496.

Tiny
Smipple2
Apr 23, 2009.
Ok lets work on the P1496 code first this one is most important as this one has to do with supply voltage to more then just the A/C clutch.
First I need you to disconnect the throttle position sensor and then turn key on engine off and check for 5 volts to the brown wire with the red stripe. If it is less then 4.5 volts then plug that back in and unplug the map sensor and check for voltage at the dark green wire with the yellow stripe. If that is less then 4.5 volts then plug that back in and unplug the A/C pressure sensor and check for voltage there. If that is less then 4.5 volts then we need to check the PCM wiring for any shorts. So get back to me with what you find here and we will go from there. If you are not sure what is what then just get back to me and I will include a pic of the TPS and the MAP sensor ok. Thanks.

Racefan966
Apr 24, 2009.
Disconnected TPS, no brown wire with red stripe. Voltage to orange wire with blue stripe, (center) is 4.18. Purple with white stripe is 5.00. On map sensor, dark green with RED stripe is 4.11, and purple with white stripe is 5.00. AC pressure sensor, purple wire with white stripe is 5.00 volts. Thanks again.

Tiny
Smipple2
Apr 24, 2009.
OK good that means that this part of the wiring is good and all this is tied together for voltage. Now unplug the ac compressor and turn on the ac and check to power to the clutch one of the wires should be hot. Now if there is power there then you need to check the ground and see if it is good. Now I also need you to check fuse number 7 in the under hood relay fuse box should be a 10 amp. Let me know what you find here. Next I want to check the A/C compressor relay as this is what turns the a/c clutch on depending on what you find here. Get back to me. Thanks.

Racefan966
Apr 25, 2009.
The wiring to the AC clutch is good. There is no fuse in #7 spot, but # 9 for " relays" is a ten amp and good. The problem lies, as I stated at the outset, that there is no ground to the COIL side of the AC relay. (Slot # 39 in the fuse block for the AC relay is hot. Slot 31 becomes hot when the relay plulls in, and energizes the clutch. Slot # 19 is hot when the key is on, and slot 21 is the ground side of the relay coil and apparently is controlled by the blower switch inside and? Else.) When I add a ground to the coil side of the relay, (slot # 21), the clutch pulls in and the AC cools, but the coolling fan does not come on, and head pressue goes too high, (Over 300#) so the ground side of the relay apparently controls, not only the relay, but also the operation of the cooling fan, (There is only one--both for the radiator, and the
ac condenser.), When the engine temp is low. Thanks Again for all your trouble.

Tiny
Smipple2
Apr 25, 2009.
The blower motor switch is grounded behind the instrument panel in the center. All the other grounds are at the right front fender. What I see is 4 wires to the A/C clutch relay. The green one goes to the power control module, the green with red stripe goes to the temp switch on the compressor, the black wire with the red stripe is power in from the fuse box, and the black wire with the white stripe goes to the compressor and grounds there. This is based off the wiring diagram for a 97 Sebring LX 2.5 ltr. If any of this info is wrong get back to me with the right sub model and I will look it over again.

Racefan966
Apr 25, 2009.
Checked the wiring from the AC relay socket, coil side, to the terminals in the pcm socket, (green wire) and found no continuity. Yet, from that socket to the hot side of the battery, the meter reads 3.14 volts, so there is a partial ground there, but not enough to pull iin the relay. Where can I buy the proper wiring diagragm for this car? It is a '97 sebring convertible with 2.5L. The nearest one I have is for a '99-2000 coupe, and is evidently not correct. Any other suggestion you have as to what to look for would be greatly appreciated. One other thing, some time back the pcm was replaced, and it was about that time that the AC quit. Coincidence. Maybe. Thanks again for all your trouble.

Tiny
Smipple2
Apr 26, 2009.
The haynes manual number is 25040. You can buy it a haynes. Com or call around to your local parts stores one of them should be able to get it for you. Hope this helps.

Racefan966
Apr 27, 2009.
Thank you.I already had the Haynes manual, & the chrysler dealer gave me the diagram for the '97.
Everythiing checks out ok so far, including the evap. Temp sensor and wiring, but the pcm is still not sending the proper signal to the AC relay to pull it in. Probably something simple I am overlooking. Thanks again for all your help.

Tiny
Smipple2
Apr 30, 2009.
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