Engine Temp Senor and Engine Thermo Switch wire color codes for Mainship

[PColaSun]

Hello,

I have a new to me, 95 Mainship Sedan Bridge 31 w/ a pair of Yanmar 6LY-UTE engines. Quick question regarding engine temp sensor and overtemp thermo switch. Which color factory wires go to the sensor and which color goes to the thermo switch? My engine wiring doesn't match. Meaning port engine doesn´t match stbd engine. Should the temp sensor be tan/blue or tan/red? What color for the thermo switch? tan/red or tan/blue? The parts breakdown in the service manual doesn´t give the most accurate depiction. Also, does it matter which hole they are installed? I bought the boat a few months ago and after looking at the wiring...it doesn´t look accurate..as I keep having low temps readings at the helm. I replaced the stat and temp sensor today with no luck on matching temps readings at the helm.

 

[TowLou]

Did you verify the temperature with a infrared gun if the guage is reading correct? How low is to low? What is the water temp coolant and sea? How hard and long did you go out?

 

[PColaSun]

Thanks for the help in advance.

I did verify it with an IR gun. Gauge is lower than the engine with IR gun by (15 degrees). I haven't had it out of the slip yet..plan to do that tomorrow - pending weather. Sea water temp is around 69F. The highest the engine coolant ever got at the dock after I replaced the stat and sender was 145F after 30-40 mins running.