I have an intermittent alarm that has gotten steadily worse since last season. It only happens after engines are warmed up. I’m guessing it’s temp alarm (drive reservoir full).
I finally diagnosed it to the starboard motor which runs about 176-177 on the gauge. Port is about 175.
I’m ready to throw some parts at it before paying the marina to troubleshoot as the parts are relatively cheap. My guess is faulty sensor since it sounds like Morse code. I may buy an IR gun just to confirm nothing else is going on. I have a few questions;
1) is that operating temp normal?
2) what areas should I hit with the gun and what’s normal vs cause for concern?
3) I can’t get a clear explanation online which sender is the helm gauge vs alarm. Does anyone have the PN for the alarm or can confirm which side of the manifold it’s on.
4) I plan to replace the thermostat as well. Is it an easy job to replace thermostat and sensor? Anything I should be aware of beforehand?
4.3 carb alpha 1, raw water cooled.
Thanks!
BTW - painters tape over the engine alarm speaker did the trick to diagnose which engine (both alarms sound identical). If you have another trick please share!
The alarm sensor has the tan/blue wire while the helm gauge has a solid tan wire. I would first disconnect the tan/blue wire and operate the boat for some time to confirm the alarm doesn’t sound. If it still sounds I would try disconnecting the oil pressure alarm sensor and finally gear lube until you isolate the issue.
Thermostat and alarm replacement
Linear Mode
