2001 jetta vr 6 battery keeps draining - 2001 Volkswagen Jetta TDI

Make sure the sunroof water drains are clear, they are at the corners of the open sunroof in the body structure, the roof is not designed water tight, it depends on the water drains to keep from leaking

your battery could be old and not keeping the charge. you could get a new battery...

something is draining your battery, I would take it to an automotive electric mechanic .

If you suspect the alternator, disconnect the 12V line coming directly from the battery and check for current drain. Are you sure the current unit is in ampere (A) and not milliampere (mA)? A 5A current will drain your battery in about an hour. A 5mA current is just about normal considering the parasitic load (radio memory chip, clock, ECM memory circuit, etc.). Try checking your battery. It could be the real culprit.

Your Jetta has a block heater available. It plugs in and keeps the block warm, making it easier to start. Below is a link with step by step instructions for battery replacement.

01 Jetta Battery Replacement

what is happening after you close the doors and lock it.. you may have a parasitic drain coming from a computer if everthing doesnt shut off or you just may have a bad battery or alternator. A bad diode in an alternator can drain a battery even when car is not in use

did you checked you fuses make sure they are not burned.

My wife's 2001 Jetta TDI had the same problem. First we changed the battery. (It was just about due anyway) No change. We then traced the power drain to the in-trunk mounted CD changer. This was an aftermarket CD changer but we went to the same source that the VW dealership uses. Of course one blames the other. The CD changer was even replaced with no change. If we are not using the car for long trips we unplug the CD changer and no more dead battery! Neither the VW dealer nor the AV installer could give us a good working solution to this problem.

Th cowling let in fresh air for the heateer and defroster, Their is a drain in the bottom of the cowling or heater ductwork which allows the water to escape before going into the car. I woudl gues that the drain is stopped up..

Yes you can get a shorter belt and bypass the ac. It may be as simple as going to the parts store and tell them you have 2001 jetta no ac. Just keep the receipt.
You should also disconnect the a/c compressor connectors/wires/plugs also, try doing this before you bypass the ac first incase doing so gives you warning lights on the dash board.
Also know that the defrost setting uses the a/c so it will take longer to get the condensation off the inside of the window.