Ford 500 A.C Problem. Plz help
#1
09-15-2018, 03:01 PM
Ford 500 A.C Problem. Plz help
I have a 2007 Ford Five Hundred, 3.0L DOHC Duratec V6 with the 6spd Trans. My problem is that the A.C Compressor does NOT come on. I am very mechanically inclined and here's the process I've done this far.
*I've tested the 2wire (green/black) to the A.c clutch and is has NO power to it.
*I've check ALL fuses and relays. More then once
*I've replaced the A.C pressure switch(3wire on the compressor line)
*I've replaced the Cabin Air temp sensor, located in the EVAP box.
*I've checked the A.C Freon level. Not running I can't get an accurate read but it has enough to start
I still get NO power to the A.C clutch this is won't engage. Can anyone help me plz? Thank you so much
*I've tested the 2wire (green/black) to the A.c clutch and is has NO power to it.
*I've check ALL fuses and relays. More then once
*I've replaced the A.C pressure switch(3wire on the compressor line)
*I've replaced the Cabin Air temp sensor, located in the EVAP box.
*I've checked the A.C Freon level. Not running I can't get an accurate read but it has enough to start
I still get NO power to the A.C clutch this is won't engage. Can anyone help me plz? Thank you so much
#2
09-17-2018, 09:58 AM
Auto or manual temp control?
PCM controls the ground leg of the A/C clutch relays coil side. If the below checks prove out, double check the A/C pressure transducer sensor for VREF BN-WH, signal on RD-PK.
The Evap discharge air temp sensor, signal on the TN-OG.
Checked the relays how so? Do you hear it click when commanded on?
If your certain all the fuse protections are good, not just visually, remove the A/C clutch relay and on socket pin 87, use a meter and check resistance from socket pin 87 to the LG-OG on the field coil connector.
Also, check socket pin 86 for hot in Run/Start, 30 for Hot at all times to double check fuse/power distribution to the relay...
PCM controls the ground leg of the A/C clutch relays coil side. If the below checks prove out, double check the A/C pressure transducer sensor for VREF BN-WH, signal on RD-PK.
The Evap discharge air temp sensor, signal on the TN-OG.
Checked the relays how so? Do you hear it click when commanded on?
If your certain all the fuse protections are good, not just visually, remove the A/C clutch relay and on socket pin 87, use a meter and check resistance from socket pin 87 to the LG-OG on the field coil connector.
Also, check socket pin 86 for hot in Run/Start, 30 for Hot at all times to double check fuse/power distribution to the relay...
#3
09-17-2018, 12:29 PM
Auto or manual temp control?
PCM controls the ground leg of the A/C clutch relays coil side. If the below checks prove out, double check the A/C pressure transducer sensor for VREF BN-WH, signal on RD-PK.
The Evap discharge air temp sensor, signal on the TN-OG.
Checked the relays how so? Do you hear it click when commanded on?
If your certain all the fuse protections are good, not just visually, remove the A/C clutch relay and on socket pin 87, use a meter and check resistance from socket pin 87 to the LG-OG on the field coil connector.
Also, check socket pin 86 for hot in Run/Start, 30 for Hot at all times to double check fuse/power distribution to the relay...
PCM controls the ground leg of the A/C clutch relays coil side. If the below checks prove out, double check the A/C pressure transducer sensor for VREF BN-WH, signal on RD-PK.
The Evap discharge air temp sensor, signal on the TN-OG.
Checked the relays how so? Do you hear it click when commanded on?
If your certain all the fuse protections are good, not just visually, remove the A/C clutch relay and on socket pin 87, use a meter and check resistance from socket pin 87 to the LG-OG on the field coil connector.
Also, check socket pin 86 for hot in Run/Start, 30 for Hot at all times to double check fuse/power distribution to the relay...
#5
09-17-2018, 02:28 PM
Here's what I have. I tested the power while the car was on for each of the following and these are the readings...
*RELAY 50
87. .03V. 85. 11.31V
30. 12.31V. 86. 0.0V
*RELAY 43
1. 12.21V. 3. 12.21
2. 0.0V 5. 0.0V
*FUSE 24
12.21V
*FUSE48
12.21V
*DIODE 40
0.0V
Here's the readings for the following SENSORS
*A.C CLUTCH SWITCH
RED. 1.96V
ORANGE. 0.0V
BROWN. 5.05V
*A.C EVAP TEMP SENSOR
ORANGE. .63V
GREY. 0.0V
*A.C CLUTCH TO COMPRESSOR PIGTAIL
GREEN. 0.0V
BLACK. 0.0V
*RELAY 50
87. .03V. 85. 11.31V
30. 12.31V. 86. 0.0V
*RELAY 43
1. 12.21V. 3. 12.21
2. 0.0V 5. 0.0V
*FUSE 24
12.21V
*FUSE48
12.21V
*DIODE 40
0.0V
Here's the readings for the following SENSORS
*A.C CLUTCH SWITCH
RED. 1.96V
ORANGE. 0.0V
BROWN. 5.05V
*A.C EVAP TEMP SENSOR
ORANGE. .63V
GREY. 0.0V
*A.C CLUTCH TO COMPRESSOR PIGTAIL
GREEN. 0.0V
BLACK. 0.0V
#6
09-18-2018, 11:47 AM
It looks like the A/C isn’t being commanded On..
So, 30 Hot at all times.
86 Hot in Run Start
87 is AC Field coil/load
85 is ground for the clutch relay PCM controlled..You can verify selective grounding by putting your meter on 85 (3) and look for continuity/ grounding when A/C is selected. You’d also feel/hear the relay click when inserted if active.
Id bet it’s missing, and the manual AC climate control module utilizes an AC allowed request signal sent to the Instrument cluster which relays the request to the PCM.
So, 30 Hot at all times.
86 Hot in Run Start
87 is AC Field coil/load
85 is ground for the clutch relay PCM controlled..You can verify selective grounding by putting your meter on 85 (3) and look for continuity/ grounding when A/C is selected. You’d also feel/hear the relay click when inserted if active.
Id bet it’s missing, and the manual AC climate control module utilizes an AC allowed request signal sent to the Instrument cluster which relays the request to the PCM.
#7
09-21-2018, 06:42 PM
I took the car to the dealer to make sure before I spent the money. I'd rather spend $100 on a diag fee then waste a few hundred on a PCM. The Ford Dealer diagnosed it as a faulty PCM and recommended that it be replaced and this would fix my Air Conditioning issue, send signal to the A.C clutch to turn on. They also jumped the compressor and it kicked in and blew cold air.
#8
10-03-2018, 06:51 PM
Please help...id appreciate any advice and you are knowledgeable. I replaced the PCM with a reman unit using my VIN and uncut keys as recommended by the Ford Dealer. My A.C still DOES NOT WORK. They spent more time diagnosing the issue and and up with NOTHING I didn't know. The technician says this...
*All relays and fuses are good and get power
*A.C CLUTCH cycling switch is New
*EVAP Temp sensor is New.
*A.C pressure are in range
*The parameters for sensors are in range
He told me directly he has NO idea what is wrong. This is twice! The A.C clutch is NOT getting power. But when jumped he showed me it works. I replaced everything except the A.C CONTROL PANEL. If when switched to A.C or Max A.C and there is a solder joint broken or wire then the PCM won't get the signal to turn on. I mentioned that to the Tech and he says '"the A.C light illuminates indicating it has power" but does it? Also do you know or have a diagram of the A.C system? Thank you so much.
*All relays and fuses are good and get power
*A.C CLUTCH cycling switch is New
*EVAP Temp sensor is New.
*A.C pressure are in range
*The parameters for sensors are in range
He told me directly he has NO idea what is wrong. This is twice! The A.C clutch is NOT getting power. But when jumped he showed me it works. I replaced everything except the A.C CONTROL PANEL. If when switched to A.C or Max A.C and there is a solder joint broken or wire then the PCM won't get the signal to turn on. I mentioned that to the Tech and he says '"the A.C light illuminates indicating it has power" but does it? Also do you know or have a diagram of the A.C system? Thank you so much.
#9
10-03-2018, 08:24 PM
Remember,, the Panel sends an AC request signal to the instrument cluster module, which ‘then’ sends the command to to the PCM for control...
Auto temp systems are self diagnosis capable in part, as well as a full step procedure for diagnosing the system ops available.. But the manual control doesn’t have much workshop info or procedure to trouble shoot them.
I’ll look to see if we can determine a signal out of the temp control head..
Auto temp systems are self diagnosis capable in part, as well as a full step procedure for diagnosing the system ops available.. But the manual control doesn’t have much workshop info or procedure to trouble shoot them.
I’ll look to see if we can determine a signal out of the temp control head..
#10
10-03-2018, 10:23 PM
Here's the conditions/parameters that need to be met for AC clutch engagement..
The climate control assembly is set to a mode which provides an A/C request to the PCM via the instrument cluster module (ICM).
The evaporator discharge air temperature sensor is reading a temperature above 4°C (39°F)
The A/C pressure transducer is not reading a pressure above 2,841 kpa (412 psi) in the high side of the refrigerant system.
The A/C compressor relay is switched to the CLOSED position by the PCM.
The engine coolant temperature is not excessively high.
The PCM has not detected a wide open throttle (WOT) condition
Might look for a switched ouput value back probed either at the climate control assy. connector (pin 3 TN/BK wire) or at the Instrument cluster connector pin 10 same wire color/tracer as the climate control..
The evaporator discharge air temperature sensor is reading a temperature above 4°C (39°F)
The A/C pressure transducer is not reading a pressure above 2,841 kpa (412 psi) in the high side of the refrigerant system.
The A/C compressor relay is switched to the CLOSED position by the PCM.
The engine coolant temperature is not excessively high.
The PCM has not detected a wide open throttle (WOT) condition
Might look for a switched ouput value back probed either at the climate control assy. connector (pin 3 TN/BK wire) or at the Instrument cluster connector pin 10 same wire color/tracer as the climate control..
Last edited by Hayapower; 10-03-2018 at 10:25 PM.