Yes, that is the way to do it.  If you measure ohms you need to have the
dash end of the wire unplugged. If you measure voltage you can do it
with everything connected.

Mark

Aaron wrote:
> So it sounds like the yellow wire should be open, then have continuity to ground if oil pressure goes above 10-15 PSI. Can I just test that will my multi-meter with harness connector unclipped, or should I probe the wire while the harness is connected?
>
>