Ac grinding noise when it's engaged after sitting a day or so
 

1996 E350 AC grinding noise
Been wondering for a long time now, with AC on, and van has been sitting for around a day or 2 it's grinding for a second after starting the engine, is it damaging something? Could it be the clutch? Please help

If,,,,,,,
the engine starts fine without any noise with the A/C off Good just make sure the A/C is off when starting the engine.
What happens if you turn the A/C on with the engine already running?
If that noise comes on then , there is a good possibility the A/C clutch is coming down with a problem and might need to be replaced. Before replacing or having it replaced a check should be made to confirm good connections at the clutch because insufficient power there could cause the clutch to slip on engagement. Let us know what you find, Thanks

Ok, so I should check if it's getting enough volts when it's starting?
Guess I could check the wires going to the clutch.
I'm really unsure, but I don't think it's doing it once it's running and I start the AC, also it's kicking in smoothly with defrost on to check how it's cycling.

Given the vintage and probably mileage if original, the air gap in the clutch hub may be excessive causing the clutch to slip on first engagements.

Too wide a gap and the magnet has a hard time locking the clutch, Generally causing intermittent cycling drop outs, and could still certainly be comp. or clutch application problems, but gap is an easy fix and can cause locking issues..

Yes, it's still original clutch, might be the problem, how to I adjust gap and what should the gap be, could check it out this afternoon if I knew how it works, I have a good puller to take it off and check it out.

Air gap is generally about 0.030". Checked with a feeler gauge. If the clutch face is warn uneven the reading may be off or harder to gauge. There's shims between the splined nose/shaft of the compressor and the outer plate of the clutch. Remove a shim to close the gap if needed.

Since Ford puts their A/C compressors down low, it could just be chugging oil out of the compressor that has settled in the compressor pistons after setting over night or longer.

thanks guys, i think it's fixed, i took out the plate and it was packed with crud so it couldn't completely click into place, now it has a distinguished click when it's engaging, works good, but now i have a bigger problem.... will ask it in a new thread.