yoonsoo

I recently got a 2001 Taurus SES with 3.0L Vulcan engine.
Previous owner told me a new (or used) compressor installed less than a year ago but now A/C is not working. Heater is working fine.

1. Compressor clutch is not engaging at all.

2. Low pressure cutoff switch is close that means refrigerant level is okay.

3. Checked low pressure port pressure also, it has full pressure.

4. Plugged out the electric connector in the electromagnet of A/C clutch, checked the voltage (14+ volt). It seemed okay but the plastic locker of the electric connector was broken so connection is really loose. I'm not sure about this electric connection to the electromagnet since connector is so loose and it is really hard to check two pins of the male connector in the electromagnet.


Any thought/experience and comment are welcome.

*** I also have some grinding sound (low frequency) from the bottom/rear (not sure?) of the car, especially the engine is not warmed up. Will this also be bad clutch bearing?

I will bring the vehicle to mechanic for A/C check-up, but they probably give me a $1000-$2000 quote replacing the whole A/C system. If I am confident what the problem is, I can ask them to replace bad parts only instead of whole system.

Thanks.

yoonsoo

Any help will be welcomed.
I went to mechanic today to change breaks and also asked check for A/C.
They only say no power to compressor (although I saw +14v on connector) and they need to figure that out in a later time. I need to double-check fuse and relay for A/C but is there anything in your mind in this case??

Thanks..

yoonsoo

Another update:

I found out that A/C cycling switch is not working now but with addition of fused link at A/C cycling switch harness keep the +14 voltage on Clutch coil connector.

What I'm guessing now is what if two metal pin of clutch coil are broken. I think it might be possible because I can't feel anything when I put my finger (it doesn't have room to poke in but I tried) or I don't really feel any force of insertion when I insert electric connector to the coil, It's just loose.

I tried to see the pin using small mirror, not yet succeeded. I will try it again.

Please let me know if you have any idea of checking broken metal pins of clutch coil or some other experience.

Thank you.

tbird100636

Okay, I dug up my 2001 Taurus/Sable Shop manual to find out the operating parameters. The A/C clutch gets power from the A/C clutch relay, which is operated by the PCM. You said there is voltage at the Clutch connector. But you did not mention about checking the other side of the circuit, the ground circuit. The clutch is grounded at all times. So with an ohmmeter hooked to the negative post of the battery and the ground wire pin in the clutch connector, you should see below 5 Ohms. If you don't than you found the problem. To further confirm this get a good thicker gauge test lead (not the cheapy thin kind that will melt, as this is a high current circuit.) and clip one end to the negative battery post, and back probe the ground wire at the clutch connector. If the clutch works, you deffinitevly diagnosed a bad ground wire. A note- Look closely at where the wire enters the connector. I have seen many clutch connectors with a broken wire right where it goes into the connector. This is ussually caused by the wires being tie strapped to tight to the engine or subframe. The rocking of the engine evenually causes the wire to break internally first. the insulation looks fine of may be slightly faded at the break. If you can pull the wire apart with light pressure than you found the problem. If this is the problem, get a new clutch connector and make sure the wires aren't tied as tight as the factory did it. Hope this helps.

yoonsoo

I checked the groud of the clutch connector. First connector looks okay. When I checked the resistance between negative end of the connector and battery (-), resistance was 1-2 ohm when engine is off but it goes up like 25 ohms if I turn on the engine and switch A/C on.
Thanks.

tbird100636

Sounds to me like your probing the wrong wire. The Black/Yellow is the power for the cluctch and the Black is the ground. This would explain the increased resitance with the key and A/C on

yoonsoo

Thanks tbird100636,

I checked power and ground wires right. According to 2001 manual CD I downloaded from fordcds.com, we need to check the resistance between ground pin in clutch coil connector and battery (-) terminal with A/C off. And it should be lower than 5 ohm.

Today I put inspection mirror around the connector port and check if two male pins in the clutch coil are intact. There are two pins inside of white plastic but clutch power pin is a a little bit shorter than ground pin. I'm not sure whether they are designed like that (in order to touch the ground first) or somehow power pin is damaged and get lowered.

I think I need to check the clutch coil connector. The plastic lock has been broken (it shouldn't be matter) and I can't feel ANY force/friction when I try to put it into the clutch coil. Somehow it is TOO loose. I can get a replacement connector around $15 then I can check whether my coil or connector is bad.

Thanks for any suggestion!!!






I'm not sure

yoonsoo

Finally I fixed the problem. I bought a new electric connector for clutch coil and can understand what was going on by dissembling that connector. One of the male pins on clutch coil somehow pushed back so there were no contact at all...

I put small clamp connectors to hold two pins and I could run the clutch and add some refrigerant.... now a/c is working.

Thanks.