On Thu, 01 Jul 2004 01:29:32 -0400, "Wm. E. Fletcher"
wrote:

Twin inboards, Mercruisers. Starboard temperature gauge does not work.
I wired in a new gauge- still won't. work.. Need diagnostic approach
to decide if the heat sender, wiring, gauge, bad ground, etc. is at
fault. Thanks, Bill

With the ignition on, engine OFF, put a Volt meter on the wire to the
sender unit, and Ground. Do this on both motors for comparison. My
guess is they should both be around 12 Volts.

If both readings are close, swop out the 2 sender units, since you
know the Port unit is good. If you still get the same results, suspect
wiring.