Originally Posted by
stinger608
It's Good you only ran it for a few seconds.
That is pretty much narrowing it down then. You might pull, or have someone pull the Alternator and fan out and take a good look at the fan. It could be a broken or loose blade that causing it also. I had that happen many years ago on a Baja bug. Also, if the trike sat for any length of time, it could be part of a birds nest or mouse nest. Seen that several times on bugs that sat for a long time. It will throw the balance way off.
If there isn't anything odd in or about the fan, then I have to suspect it being the alternator.
See if that that fella that deals with VW's has an extra alternator and fan set up to give it a try.