Wondering what things I should look at. Boat is basicly new and gauge doesn't register when I turn on the ignition. I also swapped out all the gauges on the dash, went from Faria to Gaffrigs from my old boat. All other gauges work fine, all wires on fuel gauge look correct. I assumed tank was empty so I added 40 gallons. When key is turned on, the needle goes even lower on the dial. I checked the wires at the sender which were connected with butt connectors. Things appeared OK, but I wasn't sure of the connection so I cut it out and put a 12 volt tester with a bulb in the handle across the two wires and energized the ignition. The fuel gauge read full and the bulb lit up dimly. I was wondering if this would indicate that the wiring was OK but the sender was faulty? My electrical prowess is one level above changing light bulbs, and that may be generous. What do I do next? Thanks! Steve

If you are turning the key on and it is going more to the left you have a short to ground, or the gauge doesn't work the same as the old one. put the old one back in and if it works maybe you don't have it hooked up right . Or your sending unit is bad.

Doesn' t the fact that the gauge reads full when I connect the cut wires at the sender indicate wiring is good and the sender faulty? Steve

Bad sender if you short the wires and it pegs to full

Thanks Magicfloat! That's what I was thinking. Steve

yes, or just a stuck float. If it sat all winter with no gas it might just be rusted together take it out and run it with a full tank and see if it frees up

I pulled the sending unit and the float was free. Re-installed and re-wired, still no luck. I'll call Sonic and order a new sender. Thanks for the replys! Steve

The sender may not be compatible with the gaffrig unit...may have to get the adjustible gaffrig sender

Gaffrig uses the 30-240 ohm sender like everyone else in boating. The senders are pretty much an off the shelf item.
It may be easier and much cheaper to take the old one out, go to a marine supply store and buy a new one rather than getting it from Sonic. They're only about $25.
Gary

Isn't there a much better electical sender for these POS-s?