[Vwdiesel] woo-hoo-WE HAVE TACH! 1 more question though...

[Michael Smith]

Hello all dieselheads.....

Well, I found the source of my problem.  I couldn't for the life of me
figure out (after finding it buried in the sheath) how this super short red
wire with black tracer could've been going to the alternator to power the
tach sensor (is this the correct term?). It's way too short--(It must have
been at one time, but not since I've owned the beast).
Today, with a fresh mind I popped the hood of the Jetta and looked around.
Lo and behold I noticed that there was an "extra" green wire running
directly from the battery, tie wrapped up along the rad and down towards the
alternator.  In the past I had always dismissed this as a long gone fog
light circuit, air horns, or whatever some PO must have installed at one
time.  I looked at it more closesly and saw that it indeed had a spade
terminal on it.  I stuck it onto the alternator into the recessed spade
(thanks to whoever told me to look 80degrees away from the main lug, that
really helped in the dim early morning light w/o a flashlight !) and stuck
it on. Voila, we have tach !

My question is, will there not be current draw (all the time) with this
sensor wired directly to the battery?  The red/black wire surely must be
switched 12VDC is it not?  I can only presume this red/black wire is broken
or whatever relay powers it is not working, etc.

I know how to run a multimeter, etc. etc., but I didn't have time to do any
testing this morning before coming to work.  I thought maybe someone might
know off hand.

Thanks!

Mike