I’m not fixated on the low voltage input code
I’m suggesting . . . as I stated earlier . . . that the coolant temperature gauge may in fact be reporting the correct values
I’m suggesting this because fan operation seems to affect the coolant temperature gauge reading
Those 4.3 liter V6 engines were absolutely notorious for blown lower intake gaskets, which is a situation which could lead to elevated coolant temperature
You’re concentrating on the low voltage input code
I’m more interested in the actual coolant temperature, and why it may be high
Have you even used a 2nd method . . . such as an infrared or laser thermometer . . . to determine the actual coolant temperature?