I have a Mercury 150 blk max and i just installed all new gauges (Tach,Fuel,Trim,Mph,Temp,Pressure.volt ) All work fine except the volt meter. It only show about 11 1/2 volts. Checked it from the rectifier and it shows 12 1/2 at idle and up to 13 1/2 at about 3k.
I guess my ? is does it pass through someplace else after the rectifier that could be bad, or could the gauge be bad. I have double checked my wiring and i don't think it is that but i have been wrong before
Any help/tips would be greatly appreciated.Can't you check the voltage at the contacts on the gauge (using your hand-held voltmeter)? That can rule out a bad voltmeter (the one mounted to your boat, not the piece of test equipment ) Good luck.