At 12:21 PM 6/2/2011, Jonathan Edwards wrote:
>First off - do I need to run a wire all the way back to the coil, or is
>there a wire already from the coil to somewhere in the dash? (I only ask
>because I know some '85s came with a tach from the factory, so maybe that
>wire is part of a wiring harness?).

Look for a green wire on pin 9 of the panel connector.  I'd be
moderately surprised if it weren't there.

But I do think if you have access to a panel with a tach that you'll
be very happy with it.  I think Don went considerably overboard about
the difficulty of rearranging the wires in the panel connector to put
an '85+ panel in an '84- van - the connector folds open almost as
though they expected you to want to rearrange things - but
regardless, you won't have to do that.  If you get a later panel with
an L-board installed into the speedo housing, you'll need to ground
pin twelve to keep the "Dynamic Oil Pressure System" happy; and if
you can't easily get hold of a wire with the right terminal on it
along with the panel, the OXS wire is an obvious candidate for scavenging.

Yours,
David