ac compressor clutch will not engage
Thread Starter
Joined: Apr 2024
Posts: 2
From: mitchell SD
ac compressor clutch will not engage
I have an 05 accord and have had issues with my ac for the past 2 years. i have replaced the compressor, pressure switch, high side and low side valves, all fuses and relays and my ac will still not blow cold. before you ask, yes i have purged and recharged my freon many times and i have even taken it to a shop to have it done professionally. i have come down to the point that i know its an electrical issue. i sent power to my compressor and the clutch immediately engaged. i believe that one of my wiring harnesses are the issue. all wiring in the harness that’s under the hood are intact but im not sure about the one behind my dash. does anyone have any ideas that may help me figure what’s wrong? with summer coming around again i want it fixed
Super Moderator
Joined: Sep 2006
Posts: 16,331
From: Houston, TX
Lets just start with some basics to ensure nothing was missed.
Check for HVAC codes on your car. See the common diy thread on top of the gen tech help forum for directions.
Does your car have climate control where you can control the temp on both sides, or do you have one temp setting for the car?
When your car is running and you turn on the a/c, does any air (hot or cold) blow through the vents?
When you turn on the a/c with engine running, do both fans on the radiator turn on? I'm assuming the a/c clutch does not turn on?
Check for HVAC codes on your car. See the common diy thread on top of the gen tech help forum for directions.
Does your car have climate control where you can control the temp on both sides, or do you have one temp setting for the car?
When your car is running and you turn on the a/c, does any air (hot or cold) blow through the vents?
When you turn on the a/c with engine running, do both fans on the radiator turn on? I'm assuming the a/c clutch does not turn on?
Thread Starter
Joined: Apr 2024
Posts: 2
From: mitchell SD
Lets just start with some basics to ensure nothing was missed.
Check for HVAC codes on your car. See the common diy thread on top of the gen tech help forum for directions.
Does your car have climate control where you can control the temp on both sides, or do you have one temp setting for the car?
When your car is running and you turn on the a/c, does any air (hot or cold) blow through the vents?
When you turn on the a/c with engine running, do both fans on the radiator turn on? I'm assuming the a/c clutch does not turn on?
Check for HVAC codes on your car. See the common diy thread on top of the gen tech help forum for directions.
Does your car have climate control where you can control the temp on both sides, or do you have one temp setting for the car?
When your car is running and you turn on the a/c, does any air (hot or cold) blow through the vents?
When you turn on the a/c with engine running, do both fans on the radiator turn on? I'm assuming the a/c clutch does not turn on?
my car does have a dual sided temperature regulation, when I turn the vehicle onto accessory, I cannot turn any of the fans on. the engine is running both fans and radiator does turn on, but the clutch will not engage with any of it and when I had replaced the compressor the first time it would work for a couple minutes and then it quit
Super Moderator
Joined: Sep 2006
Posts: 16,331
From: Houston, TX
Per the wiring diagram, I don't think the blower fan will work unless the key is in the II position.
Checking for HVAC codes is a simple first test, so give that a shot.
Since the 2 radiator fans turned on when you switch the a/c on, I'd test at the a/c compressor relay. Remove the relay. The relay will have 4 pins, where two are large pins typically copper the other two are smaller pins. Use a volt meter with the black meter lead touching the - battery post, key in the II position, and use the red meter lead on each socket in the fuse box. One large socket and one small socket should have 12V. With the engine running and the a/c turned on, the other large and small pin should have ~zero resistance (continuity) to ground. Let us know if 2 pins have 12V and 2 pins have continuity to ground.
Checking for HVAC codes is a simple first test, so give that a shot.
Since the 2 radiator fans turned on when you switch the a/c on, I'd test at the a/c compressor relay. Remove the relay. The relay will have 4 pins, where two are large pins typically copper the other two are smaller pins. Use a volt meter with the black meter lead touching the - battery post, key in the II position, and use the red meter lead on each socket in the fuse box. One large socket and one small socket should have 12V. With the engine running and the a/c turned on, the other large and small pin should have ~zero resistance (continuity) to ground. Let us know if 2 pins have 12V and 2 pins have continuity to ground.
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mjquillici
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Mar 31, 2015 02:51 PM