2007 20V

[da.bell]

I already got a poll going.. for non-functional gas gauges on new '07s.. that could lead into another poll for fuel-flow meters which could lead to a recall which could lead to free fuel-flow meters! maybe not...

247, the problem with that poll is it only covers one specific year. A lot of us here have "older" boats.

Okay, mine isn't old but it's older than a 07....

Sorry, just stating the facts brotha.....

[wakeboarder247]

Ya I hear ya.. the only reason I limited it to '07 is b/c I kept hearing how they changed the fuel sending unit for '07 and how it was supposed to be more accurate and all that jazz.. maybe I will change it or open a new one once I get a lil more feedback..

[chpthril]

You 07 guys sound like you may have a prob with the actual gauge (Faria) and not the sending unit as in past yrs.

If these are wired like a typical fuel level sending unit/gauge, then there is power on one side on the gauge and the ground comes through a variable resister. When the tank is empty, the sweeper on the S/U is at the ground side of the resister (low resistance to ground) causing the needle to move to the "E", when the tank is full, the sweeper is at the opposite end of the variable resister (hi resistance to ground) causing the needle to move to the "F".

An open in the signal (ground) side will cause the gauge to read "full" all the time. A short to ground on the signal side or no 12v on the gauge will cause an "empty" reading all the time.

OR it could be wired like this:

then there is power on one side on the gauge and the ground comes through a variable resister. When the tank is full, the sweeper on the S/U is at the ground side of the resister (low resistance to ground) causing the needle to move to the "F", when the tank is empty, the sweeper is at the opposite end of the variable resister (hi resistance to ground) causing the needle to move to the "E".

An open in the signal (ground) side or no 12v on the gauge will cause the gauge to read "empty" all the time. A short to ground on the signal side will cause a "full" reading all the time.

once you know how the system works, it easy to diagnose with a simple 12v test light.

1) check for 12v on gauge - no? fix and gauge should work
2) if 12v's found, unplug signal wire from gauge. Based on info above, an open may cause the needle to sweep, if not, with the testlight aligator grounded, touch the test light to the signal terminal on the back of gauge and the needle should sweep. If adding and removing ground does not cause the needle to sweep, then the gauge is bad. If the needle does sweep, then the sending unit is bad or no ground at tank.

If I get time, I will try and confirm how mine works and take some pics and get some wire colors.