Overheat alarm, Yamaha digital tach

[FabricGATOR]

Year 2000 SX/LX150TXRY's
I just installed new Yamaha digital tach's, FMM and Speedo due to sun damage and mottled LCD's.
Just love them being refreshed and new.

I had noticed when I had a previous overheat condition (with the original tach's), that the first few overheat alarms and 2000 RPM protection mode encounters, that the engine tach would indicate the flashing overheat symbol. After a while, even though I would still overheat and go into audible alarm/protection mode, that I lost the visual flashing temp indication.

I cleared the water jacket passages with a comprehensive Rydlyme treatment. That's another story too long to tell now.

So having installed my new tachs, I figured I'd test my overheat alarm by jumpering the pink to black wire at the thermo switch. While I got the audible alarm, I still have no visual flashing thermometer indication.

What would be the usual suspect, how do I trouble shoot this system, I also want to trick the oil supply system to ensure it is working properly.

As I write this, I realize that I only jumpered one of the stbd engine thermo switch's and nothing on the port engine. By "jumpered" I unpluged the thermo switch bullet connectors and plugged the engine side into itself.

[boscoe99]

More than likely there may be a delay built into the system.

Connect the engine side black and pink wires together for just one sender. Start the motor and let it idle for a period of time. Maybe several minutes. The alarm should sound and the icon should light up.

This presumes that you have the tachometer set up correctly. And that it is the correct tachometer. The one with two four pin connectors coming from the back of it.

To test the oil warning system, remove the plastic sump on the main oil tank. Drain the oil into a clean container and add it to the remote tank. Reattach and secure the plastic sump.

Turn the key on. The buzzer should sound and the icon should flash. Oil should start flowing to the main tank to refill it. Once sufficient oil gets to the tank the alarm will stop and the icon will stop flashing.