Fuel Sending Unit / Gauge Not Working

[CraigSim]

I know there are many posts with this issue. I would hate to spend $350 on a new gauge, but I will.

Basically I am confused because my sending unit ground wire splits off into two sections. One is grounded at fill neck. One goes under the tank. I haven't seen any posts that talk about the sending unit having two grounds. Help please.

[justgary]

2 minutes ago, CraigSim said:

I know there are many posts with this issue. I would hate to spend $350 on a new gauge, but I will.

Basically I am confused because my sending unit ground wire splits off into two sections. One is grounded at fill neck. One goes under the tank. I haven't seen any posts that talk about the sending unit having two grounds. Help please.

The wire to the filler neck bonds the filler neck to the tank so you don't get a spark from static buildup when you pump fuel down the rubber hose.  The other wire most likely goes to the engine and connects at the back of the head.  On your boat, I'm guessing that it is the port head near the fuel pump.  If not there, then the starboard side where the pile of grounds meet on the head.