2000 Taurus SE 3.8L OHV 114000 miles
I replaced the A/C clutch with a new one from Advance Auto for about 100 bones. The reason I replaced it was that the clutch wouldn't engage when the A/C was on, but I measured 14.5v at the compressor field coil connector when the A/C was on. I figured it was just a bad clutch. Replacing it was a real pain, since I had to remove the compressor, but I eventually got everything bolted back up (with a new serpentine belt while I was at it) and recharged the A/C with 3 cans of refrigerant.
Started the car, set the manual controls with blower all the way up, A/C on normal, and temp set to full cold. Went to look under the hood, and no A/C compressor clutch engagement!
I jumpered the A/C cycling relay on top of the accumulator to verify that this pressure switch was not the culprit. Moving to the high pressure cutoff switch, I measured a closed red/yellow to green/white connection and an open from the black to black/yellow. I don't know if this is correct for 'normal' operation or not. I read a few threads saying the red/yellow to green/white and black to blaek/yellow can be jumpered to simulate a 'proper' operating condition and tried that, but no joy. Clutch still not engaging.
Maybe the connector to the compressor field coil wasn't making contact, I thought, so I cobbled together a wooden connector and some speaker wire and tested it on the old coil with a 12v supply and it magnetized. Moving this setup to the car, I verified 14.5v on the coil connector, but pushing it into the old coil never produced a magnetic field. It's like there wasn't enough current to drive the magnet.
The one thing that did drive the magnet was when I directly connected to the battery terminals, bypassing whatever relays and switches are between. I did the same thing to the compressor's coil and the clutch engaged. Nice cold air in the car interior.
My question is, what is chain of devices between the battery and the coil? I've got a Haynes manual that shows a Constant Control Relay Module in the chain to the compressor coil, but I read on some threads that these are not on the 2000 Taurus.
So far I know there is the A/C selector inside the car, the A/C pressure switch on the accumulator, High pressure switch on the compressor, and finally the field coil.
Can anyone figure this one out?
Sunday, August 5th, 2007 AT 9:18 PM