Temp gauge or thermostat trouble

[Yokes]

Just wondering what the best way to figure out if my thermostat is failed open or my gauge/ sensor? Is failing. I'm thinking if I short the gauge it should jump to the 250 and tell me if that is the problem.

I am also noticing my volt gauge is only reading 12volts when running. My first thought was my alternater but I checked the voltage at the battery and it is 14volts when running and about 12 when the motor is off which is what I was expecting. I'm currently trying to make my way back with the volt meter to find my issue. But it is a rats nest under the helm.

350 mercruiser mpi. Faria gauges.

I'm also looking for a pin out for the temp gauge.

Any advice will help. Thanks.

[Yokes]

So I found the cause of the temp. The little push on terminal on the back was disconnected and hidden in the rats nest! So that was nice and easy.

What is the normal operating temp for this motor? Mine looks like while it is ideling it is around 200 degrees.

I'm not sure I fully trust my gauges yet till I figure out the voltage gauge issue being at only 11 volts. Seems like a grounding issue at this point.

[chpthril]

160'ish is bout normal.

Start with a voltage drop test on the helm B+ and helm B- to see which has the loss of voltage, then work back on that circuit till you isolate the drop.