My 2001 Jetta TDI has been suffering from an overnight battery drain the past two weeks. I replaced the battery with another known good battery thinking maybe the battery was going bad, no difference (had a one year old optima red top and replaced with another standard battery - same problem). Measuring the drain I get 184 milliamps and Bentley says that 100 milliamps is normal. I removed fuses one at a time with little or no success (largest decrease was 3 milliamps and when the alarm system fuse was removed the drain increased, signifying that the alarm circuit is doing what it should). I always set the alarm when parking (setting the alarm reduces battery drain). Battery has been checked by a battery shop and found to be good, charging system checked and found to be good, alternator diodes checked and found to be good.
Any ideas?