gas gauge sending unit

[yakitup]

Recently my gas gauge became stuck on full except when I turn off the power. I suspect the sending unit might be the problem but I cant figure out how to get to it. I only see one access hole on the deck and that one just gets me to the hoses to the tank.
The boat is a 2000 237 sundeck.
Thanks

 

[six50joe]

Re: gas gauge sending unit

I've got a 1998 GS201 Fundeck and have the same problem. Last season, it also happened but the problem somehow fixed itself the 2nd time out after I first noticed it.

This season, just after Irene hit the problem happened again and but didn't go away this time. The fact that it happened after my Hurricane was knocked around a bit by a real hurricane made me think the problem is a mechanical one, i.e. a floating arm getting stuck or something. The wiring to the sender looks intact at a glance, but I can't get access to the tank without cutting a hatch into the floor, something I'm hoping to avoid.

If anyone else has experience with this I'd also appreciate your help.

Joe

 

[Failproof]

Re: gas gauge sending unit

First thing to do is verify the gauge is operational. Most fuel gauges are potentiometers, so disconnect the sending unit wire from the back of the gauge, see if that changes the reading. Clean the contacts and reconnect. Did that change it? If its a groung sensing gauge, then ground out the send terminal. Did that change the reading? If it is a ground sensing unit, then the sender has to have a good ground to the SAME ground/power system that the gauge is hooked up to. The gauge and the sending unit could be fine, but if its not grounded then it wont work.