[C320-list] Temperature Gauge

[Wandering Star via C320-list]

I have a Yanmar 3GM30 and 2000 Catalina 320, sail #707.

Was out sailing last weekend and after returning to the dock and the engine was cooled down, I noticed the temperature gauge was stuck on 160. This is normal temp when I’m motoring.

Today I disconnected the sending unit wire, engaged the ignition, and the needle immediately dropped from 160 to the left below 120. Wondering if I needed to go check the sending unit wire I decided first, to start the engine and see what happens.

As the engine warmed up, the needle on the gauge rose to 160. I turned off the engine and assumed the needle would lower itself back down to 120 but it was stuck on 160 again. The only way I could get it to drop back down to just above 120 was to engage the ignition and it would drop incrementally back towards 120. But only if the ignition was engaged. I did this over about half an hour.

Does it sound like I need to check the sending unit wiring? Or could this point more towards a faulty gauge?
Clearly, hoping just replacing the gauge would suffice as electrical is not my strong suit.
Sara
Wandering Star
Seattle
2000/707


Sara S.
Sara S.

[Michael Deslauriers via C320-list]

Sara,

I believe the gauges are analog and will keep the last set point when you
turn off the key. I believe this to be true, because somebody turned off
my boat by turning the key before pulling the fuel stop lever and the RPM
gauge needle was stuck at the speed it was when the key was turned off. I
was worried that the person had damaged the gauge, but that was a few years
ago when we first got the boat. I will confirm my thinking later on today
when I get to the boat to see if the temp needle is at the last setting.(
Hopefully I remember to check it since I never look at the gauges before
starting)

Hope this helps,
Mike
Gloria
#717