Air Conditioning/Loss of Power

[Mackab]

2000 Windstar, 3.8 ltr

With air conditioning on, I get a serious loss of power. I know some would be expected with the additional load, but I seem to have to turn off the A/C when going up hills. Is this normal for this vehicle? I also get a type of "whirring" sound from the engine when accelerating with the a/c on. Any help from all you experts would be greatly appreciated.

[vmvatbaby]

The first thing I would do is look at the Alternator. I would look for arcs and test to see if its putting out at least 13 volts, under load conditions. I had a problem with my alt. recently where it was 'on it's way out' and noticed an arc inside from the brushes, intermittently...even then it was showing a 13 volt reading. My drivabilty changed where I was losing power. Currently my new alt. puts out 14.38 volts.
Hows the van run otherwise?

[Mackab]

Everything seems to run fine except when I turn on the A/C. Then I get the serious loss of power.

[garync1]

Originally Posted by Mackab

Everything seems to run fine except when I turn on the A/C. Then I get the serious loss of power.

Is the air cold or gets warmer when this loss of power occurs??
I have 80,000 miles on my 2001 but have not did a tune up yet still runs to good. If yours has alot of miles on it, may be do for a tune up. Like mentioned above you could have a week battery or alternator this will give you the same problem you discribed. Most ford batteries last about 6 to 7 years. I have heard some get more than that. if you live up north it tends to be a little lower life spand. Your battery may just be starting to get a little weak but still able to recover,but not enough AMPS are geting to your engine to keep it performing. These are just suggestions though. Hope they help... Gary

[DRW1000]

Perhaps when the compressor turns on it puts such a huge load on the engine due to bad bearings or something similar.

[garync1]

Originally Posted by DRW1000

Perhaps when the compressor turns on it puts such a huge load on the engine due to bad bearings or something similar.

Oooooooo thats a scary thought!!! lets hope its his battery. I know the whrring sound he discribe is a worry but could be the alt. working to hard..

[Mackab]

Checked the alternator today and it puts out a steady 14.0 volts with everything on including the a/c. And mileage is 72,500 with consistant maintenance and the lower/upper manifold gasket TSB completed twice, (second with updated "green" isolater bolts).

[Mackab]

Any new suggestions?

[12Ounce]

Does the ac work .... cooling the car?

The ac compressor is pretty easy to see ... and you can do a lot of analysis by giving it a look/hear while the engine idles. Look down at the compressor when the ac is not "on" .... notice the small (1/16") air gap between the clutch and the compressor pulley. Have someone turn MAX ac on, front and rear, ....with the windows open. Watch the air gap disappear as the clutch comes in ... you will hear a "snap". If it is a warm day, under these (above) conditions ... the clutch should stay in as the ac tries to cool the vehicle. Both radiator fans should come on top speed.

If the clutch cycles in and out every few seconds, you are likely low in refrigerant. Get a recharge cylinder, with gauge, from AdvanceAuto for about $20.

If the belt slips on the clutch pulley, not turning the clutch full speed (use a flashlight), you have a larger problem.

Does the ac compressor make a loud noise? Does it stall the engine to a stop? Use a length of hose for a better "listen".

Just for reference ... I hardly ever notice an engine load when driving and using the ac on my '99.

[garync1]

Have you tested the battery,take it out and have a load test done
Even if the alt works fine it still can't hold the radio and AC and all the electrics.It does not matter if you can crank it up it still can have a dead cell and recover fine. Almost like putting a underpowered batt in something.I still would check that.