Hello, This is normal, but perhaps different for every vehicle since some seem to do it and others not. The vanagon alternator is self exciting. In other words, some residual magnetism remains in the field after the last time the engine was run. On the next startup, this tiny residual field is generates some small alternator output. When that output is high enough, it is fed back into the field windings and the field gets a little stronger, etc., until the alternator reaches full output. How much output the tiny residual field generates is of course related to how strong it is, but also to how fast the alternator is spinning. So, if the residual field is fairly strong, just idle speed gets the alternator "bootstrapped." If it is weak, perhaps a small throttle blip, bootstraps it. If the residual magnetism is very low, perhaps 2000 rpm or so is necessary. In all cases, once the bootstrap has occurred, the alternator works just fine. My '84 takes a blip after 24 hours or so, but idle is enough if driven more frequently than that. However, if my alternator took 2000 rpm to bootstrap, I would replace it. Not because it wouldn't keep the battery charged, but because of the annoyance factor. Mike
Michael A. Radtke - Z74 Voice: 602-862-4897 Bull FAX: 4853 13430 N. Black Canyon Hwy. Phoenix, AZ 85029 Email: m.radtke@bull.com |
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