Could someone please help. My engine is a 1994, 3 cyl. 60 hp Mercury. I have searched the forums here and have found how to troubleshoot the tach. My power and ground to the tach check out correctly. The tach goes to zero rpm when the ignition is turned to the on position.<br /><br />My problem is the reading from the gray "sender" wire reads a constant +12 DC volts when I unplug the tach and connect the leads on my meter to the gray wire and ground. It has +12 DC volts with the ignition on or off. The battery seems to be charging as it should.<br /><br />I have read the correct voltage should be somewhere between 3 and 8 volts AC as the engine rpm increases. Could someone tell me why I have a constant +12 volts DC on the gray sender wire that goes to the tach? What part would be defective that would cause this?
