Yamaha Anolog Temp Guage Pegs Out Unit Motor is in Gear

[Contender 03]

Hi, I hope someone can lead me in the right direction to correct a fault with my 2003 round Yamaha anolog temp. guage. With battery switches on and keys in on position, my starboard temp guage is pegged out until the boat is put into gear. Once in gear the guage appears to be normal. I don’t have the same issue with the port engine guage.

Both engines are tied into a Blue Sea e-series dual circuit switch pn# 5511e.

The boat just came back from the shop after having them fixing my bilge pumps and I am trying to avoid going back to the shop if it is a simple fix I can deal with....

Thanks for any advice!

[boscoe99]

Where is rodnut? This is way over my stupidly simple density head.

[99yam40]

Ok, lets look at it in a logical way.
what will cause a meter to read full on
bad connection (high resistance)
or short( low resistance)
maybe these things work on voltage.

motor fires up and give a better voltage input
or the vibration causes a bad connection to get better
or a short to go away.

[pstephens46]

OP didn’t exactly state the gauge is pegged at idle. He said battery on and key on. ?

[99yam40]

that is true and he said it is normal when put in gear not when started.
so no telling what is going on

[fairdeal]

not an enjoyable puzzle...how can the engine being "in gear" be a factor?

the wiring to the sender is being pinched by the shift cable -
and when in neutral position its grounding it?

[Contender 03]

Thanks for the feedback so far, I am learning quite a bit.

I guess I should of clarified in my original post that the temp gauge is pegged with battery switch and keys are in the “on” position and with the engine idling.

If I understand 99Yam40 and Fairdeal’s replies, I should inspect around the shift cable and the harness cabling that maybe pinching and cracking the wire covering causing a short.