Very Loud Interior Clicking Noise

[housebanana2]

This noise is located in some unit that is in the interior housing right under the cup holder directly behind the driver side sliding door which is not powered. The noise is definitly not the shock compressor. The unit it is coming from is a big black box with a couple of wires going into the top of the unit. When I lift off the trim piece with the cup holder the black unit is right there.

It kinda sounds like an air hammer and it only makes the noise for about 20 seconds and it only starts to make the noise directly after starting the van.

Any idea's would be most appreciated.

Thank you.

[big dave]

I think that is the rear climate fan/unit. It may have sucked in a piece of paper or something.