05 LSV Temperature Guage Not Working

[Lake Luver]

I have a 2005 wakesetter with a 340 Monsoon and there is only one temp sender I can find that must be to the ECM (which I replaced).  It has two wires (yellow and black). My temperature gauge  is not working and am trying to troubleshoot. Where would the other one be? I looked all over the engine. The black and yellow wiring for the temp sender above merges with a tan wire that isn’t attached to anything (and nothing around to attach it to).  I was told to ground the temp sensor wire to see if it is a guage problem but can’t find it.

[Eagleboy99]

Have you tried swapping connectors on the gauges?  The 05 uses Canbus and you can use any wire to any gauge.  Maybe you gauge itself (or the MMDC?) is pooched?

[notaloser]

What makes you believe there is more than one temp sender?

The yellow/black should be the only Engine Coolant Temp sender. Assuming V-Drive, ECT is aft starboard on top of intake manifold? If I remember correctly, tan is to the over-temp switch mounted somewhere aft end of intake manifold.

Have you checked your MEFI for any codes? If your ECT is bad, the MEFI will report an out of range value code.

EDIT: Scratch what I’ve said above. I just remembered there is a two-wire (yellow/black) for the MEFI, a single wire  for the temp gauge (tan) and a single wire for the over-temp indicator (brown/white).

Edited May 27, 2019 by notaloser

[formulaben]

Not sure if this is applicable to a 2005 model...YMMV.