A/C compressor
Thread Starter
Joined: Mar 2020
Posts: 7
From: ga
A/C compressor
I have a 2004 Mustang 3.9l. A/c clutch that's not engaging. I've tested both pressure switches and they are both fine. I hot-wired the a/c compressor and the clutch kicks in. I tested the voltage at the plug for the compressor, with it unplugged I have 12 volts at the wire. With it plugged in I only have around 4-5 volts. Could it be the CCRM? Thanks in advance for all the help.
Thread Starter
Joined: Mar 2020
Posts: 7
From: ga
100 psi on both high and low side with clutch not engaged. Around 35 low side and between 150 and 200 high side when I jump start compressor but after a few seconds of running Freon shoots out of the pressure valve. I replaced replaced the compressor, dryer and office tube.
Gentleman's Relish
Joined: Feb 2005
Posts: 13,189
From: AZ
When you hotwire the clutch, is the air cold or warm/tepid? Did this problem exist before or after you swapped parts?
You are probably a little low on charge. 35 on the low side is borderline too low. 30 is bare minimum but typical is 40-50 psi is the norm lowside with 210-240 being on the highside
You have freon being pushed out the high-side valve? That should not be happening out of either valve. Did you replace the Schrader valves on both the high and low side?
When you replaced the compressor etc, did you run a vacuum on the system before recharging? If not, there's your problem. Ambient air and Freon do not compress at the same rate. You'll need to evacuate your system and run a vacuum on it for about 30-40 minutes, then let sit to confirm it holds the vacuum. (This checks for leaks). Then recharge. Ideally recharging should be done by weight of Freon as stated by Ford or, you can use gauges to bring the pressures to the expected range based on ambient temperature.
You are probably a little low on charge. 35 on the low side is borderline too low. 30 is bare minimum but typical is 40-50 psi is the norm lowside with 210-240 being on the highside
You have freon being pushed out the high-side valve? That should not be happening out of either valve. Did you replace the Schrader valves on both the high and low side?
When you replaced the compressor etc, did you run a vacuum on the system before recharging? If not, there's your problem. Ambient air and Freon do not compress at the same rate. You'll need to evacuate your system and run a vacuum on it for about 30-40 minutes, then let sit to confirm it holds the vacuum. (This checks for leaks). Then recharge. Ideally recharging should be done by weight of Freon as stated by Ford or, you can use gauges to bring the pressures to the expected range based on ambient temperature.
Last edited by Derf00; Aug 30, 2021 at 02:18 PM.
Joined: Nov 2021
Posts: 1
From: Ankara
When you hotwire the clutch, is the air cold or warm/tepid? Did this problem exist before or after you swapped parts?
You are probably a little low on charge. 35 on the low side is borderline too low. 30 is bare minimum but typical is 40-50 psi is the norm lowside with 210-240 being on the highside
You have freon being pushed out the high-side valve? That should not be happening out of either valve. Did you replace the Schrader valves on both the high and low side?
When you replaced the compressor etc, did you run a vacuum on the system before recharging? If not,, there's your problem. Ambient air and Freon do not compress at the same rate. You'll need to evacuate your system and run a vacuum on it for about 30-40 minutes, then let sit to confirm it holds the vacuum. (This checks for leaks). Then recharge. Ideally recharging should be done by weight of Freon as stated by Ford or, you can use gauges to bring the pressures to the expected range based on ambient temperature.
You are probably a little low on charge. 35 on the low side is borderline too low. 30 is bare minimum but typical is 40-50 psi is the norm lowside with 210-240 being on the highside
You have freon being pushed out the high-side valve? That should not be happening out of either valve. Did you replace the Schrader valves on both the high and low side?
When you replaced the compressor etc, did you run a vacuum on the system before recharging? If not,, there's your problem. Ambient air and Freon do not compress at the same rate. You'll need to evacuate your system and run a vacuum on it for about 30-40 minutes, then let sit to confirm it holds the vacuum. (This checks for leaks). Then recharge. Ideally recharging should be done by weight of Freon as stated by Ford or, you can use gauges to bring the pressures to the expected range based on ambient temperature.
Thread
Thread Starter
Forum
Replies
Last Post
Adri Stone
4.6L General Discussion
7
Aug 6, 2020 03:58 PM