This is  my guess based on my instinct of being a person with
electrical engineering background.

Disconnect the wire from the coil that gives you 12V. If the wire
still gives you 12V then it is the positive terminal that it connects
to. The other one when disconnected should give you 0.

The wire coming from the Hal sender has the signal for your tachometer.
I am not sure if you can use it directly off the Hal sender or you
need to get it from the ECU.

David  

--- On Mon, 10/12/09, Don Hanson <dhanson928@GMAIL.COM> wrote:

> From: Don Hanson <dhanson928@GMAIL.COM>
> Subject: Electrical question (Coil terminals)
> To: vanagon@GERRY.VANAGON.COM
> Date: Monday, October 12, 2009, 11:32 AM
> Hi all, I am looking to find the Neg
> pole terminal on my coil.� Mine has a
> plastic cap on the top meaning I would have to get the coil
> all the way out,
> take off the wires and then get that cap off to see if it
> has (+) and (-)
> marks on the top, like most of them do.� Trouble is,
> mine was mounted by the
> PO in such a way that it's a real pain to get off to remove
> the wires to get
> the 'cover' off.� So, is there a way to tell which is
> which?� Mine is a
> conversion rabbit motor, so the wires probably aren't
> familiar or color
> coded.� They look the same size.� One terminal
> goes on to the hall sensor or
> the MAF box or somewhere...Two go over to the ECU or at
> least into the
> harness to the ECU.
> � With the key on, each terminal shows battery
> voltage..Same
> (polarity?)..With the motor running and the alternator
> engaged, one shows
> 13.3v and one stays at battery charge voltage.
> 
> � I am looking for a place to get a signal to my
> tachometer.
> � Which of the terminals is the "Low Voltage" or the
> "Neg" terminal, given
> those peices of info, can I tell?� Or do I have to
> take the coil out
> (difficult) and remove that shield and actually look for a
> marking on the
> coil itself?
> 
> � Thanks,� Don Hanson
>