loud whining noise
 

pulled in my driveway today and got this horrible whine from my engine. sounded like a power steering pump issue. replaced the power steering pump a few months ago but checked it out anyways and it was fine but i noticed my ac pump wasnt engaging. tried turning on the ac and no cold air. wont turn on with the fan clutch like it usually does. i checked the relay and it seemed fine. if its the ac clutch that is bad is it normal for it to whine like that. never worked on an ac system before so this is new to me.

First thing I would do would be to remove fan belt from the crank pulley, cold engine, then start the engine, you can run a cold engine for a few minutes without water pump or Alternator(battery light will be on).
This will determine that the noise(or lack of it) is coming from an accessory pulley and not from the Cam Synchronizer(common issue for the 3.0l)
Shut off engine, leave key off.

Now, with fan belt loose, spin each pulley manually, you can usually hear/feel if a pulley bearing is the issue.


A/C systems have a few pressure switches that disable the compressor clutch, preventing the compressor from burning out if pressure in system is too low or blowing out a seal if pressure is too high.
Compressor clutch is pretty simple, it has two wires, one is a ground, the other gets 12volts from the relay, but that 12volts runs thru each pressure switch, so if pressure is low that switch opens and won't pass the 12volts, same with high pressure switch, these switches are on the A/C lines, if one of these switches got unplugged no 12volts would get thru.
You can test for 12v at the clutch connector, and check ground.
I don't have a wiring diagram for 2001 Ranger but I am sure one is out there to find

You can also test the compressors clutch with ohm meter, or by giving it 12volts and a ground, you should hear it click when you do that.
There is no + or - on the clutch, it is just a coil that becomes a magnet when power flows thru it.
No, a bad clutch wire wouldn't cause "whinning", a bad clutch bearing would

i ended up pulling the compressor clutch and pulley off and throwing a shorter belt on it. noise is gone. there was a fair amount of up and down play in the clutch bearing so i figure thats the issue. is it ok to run the truck without the ac compressor? ive noticed when the fan clutch comes on the ac compressor does too. someone told me the ac compressor helps pull cold air threw the engine to cool it? all new to me..lol

No, A/C is not part of engine cooling, they were pulling your leg, or just mistaken.

A/C is part of the windshield defroster though, it will take longer to defog window without it.

You know when you have a cold glass of your favorite beverage outside on a warm day, and you grab it and it's all wet on the outside, that's condensation.
Warm air holds more moisture, when the warm air comes in contact with the cold glass it cools down and loses its moisture which ends up on the glass.

In the winter the glass in the vehicle cools down faster than the inside, so the warmer air inside comes in contact with the cold glass and cools off leaving its moisture on the window.
When you start the vehicle and turn on the defroster(no A/C) the air blowing past the window picks up some of that moisture, how much depends on it's temperature and current moisture content, as the heater warms up the warmer air can hold more moisture so window starts to defrost faster.

A/C part, remember that glass beverage above, well the A/C part in the cab gets very cold, if compressor is on, so the defrost air is passed by this part first, this removes some of the moisture in that air, it drys the air, then that dry air passes thru the heater core to get warmed up and then blows across the windshield, this dry warm air literally sucks up the moisture(fog) on the window in a few seconds.

Defroster does work without the A/C, it just won't be as fast.

i didnt no this . thanks for your help :)