Oil light with AC on

Hi,
I have a 94 Taurus with a 3.0L. I just noticed that the oil light comes on when the AC is on. The light only comes on when the car is at idle. Any suggestions would be helpfull. Thanks, Andy (UPDATE) I noticed the oil light flash on and off a little today at an idle without the AC on. Is this a sign that my oil pump is going out?

Does the engine rpm's drop when the a/c is turned on? If so the low engine speed is causing the light to come on. The engine is not turning enough rpm's to pressurize the oil sending unit. I would look to the idle speed control.

I noticed the oil light flash on and off a little today at an idle without the AC on. Is this a sign that my oil pump is going out? Thanks, Andy

I noticed the oil light flash on and off a little today at an idle without the AC on. Is this a sign that my oil pump is going out? Thanks, Andy

Not necessarily. You need to hook up a mechanical gauge to get the true oil pressure of the engine. If oil pressure stays in specs with the mechanical gauge, then the sending unit is at fault. If the gauge is lower than specs, the oil pump pick up screen could be partially clogged, the oil pump could be starting to wear out of tolerances. Oh, by the way, is the oil level full?

Engine type?
RPM range at neutral?
PRM range at neutral with AC on?
RPM range at first gear?
RPM range at first gear with AC on?
RPM range at third gear?
RPM range at third gear with AC on?
RPM range at top gear?
RPM range at top gear with AC on?

Anyways you could be facing a couple of things:
Insufficient Engine Power
Low Oil Level
Poor Oil Quality
Faulty Oil Pump
Clogged Oil Pump
To Much play in the drive belt

Flickering light is fairly common with the vulcan engine in these cars. Aparently, ford didn't design the computer program to let the car idle fast enough.