Part 1 of questions:
Using the existing oil pressure senders as an example, is it possible to use them and connect a gauge along with the existing indicator light? What I've read suggests replacing the existing one (I assume the low pressure sender?) with the VDO version and I assume that means the dash indicator light is no longer in use. I do see references to senders with a second "WK" terminal, does that enable both to work together? In this CIP1 listing they refer to it as an idiot light :-)
http://www.cip1.ca/ProductDetails.asp?ProductCode=VDO-360-023

I gather the electrical gauge relies on ohm resistance to be "accurate". I'll pick up on that thread separately.

Regards, Peter Kraiker
nextchapter.kraikerphoto.com
Toronto, ON, Canada
'82 L Westfalia 1.9 TD 5 Spd (Babe)

On 2012-08-16, at 8:27 PM, David Beierl <dbeierl@ATTGLOBAL.NET> wrote:

>> do existing senders need to be replaced
> 
> Gauges and senders are matched to each other.  For maximum accuracy an individual sender will be chosen and the gauge face hand-calibrated to match it for each increment of the scale.