1988 Thunder Craft 70 HP Merc Beeping

[Sijo0601]

My Father just recently picked up a 1988 Thunder Craft with a 70 HP Merc on the back. Runs great after we cleaned the water intake to prevent overheating. When we first fired it up, there was a steady beeping. I originally thought it was to let us know about the clogged water intake to prevent overheating, but now there's a steady water flow, but the beeping won't stop. I was wondering if anyone knew how to reset the beeping or if I'm missing something? It runs great but the beeping must mean something....

Thanks!!