|Posted: July 13 2008 at 16:28 | IP Logged
Roy (my name's Roy too...who knew)
For Gas tanks.... These are float type sending units, basically veriable resistors. Try and ID the the unit 1st. You can do this by I.D.ing the fuel guage on your control panel. They are probobly Stewert Warner matched sender/Guages, availible from West Marine. The sending unit ports are located in top of the fuel tank and look like a 2-3" round fitting with multiple securing screws, a gasket arrangment and a wire lead to it.
Both guages not working gives one pause. Suggest checking things in the system outside the sending units first. 1) Good 12vdc and ground at both guages. 2) Good sender wire continuity: disconnect the wire at the sender or at the guage and test continiuty. 3) Read a resistance from the disconnected sender connect point, across the float sender to ground. If there's no resistence (open circuit), good bet the sender's defective.
Measure tank height to match sender float length with the Mfg'rs recommended replacment part #. Purchase replacment parts first. The gasket and other parts have a habit of falling apart when handled. Try and avoid removing the sender unit before having the replacment part in hand, that way, if you need to seal up the port, you can do so with a good gasket.
Keep area vacuumed & ventalated. Avoid dripping anything into the tank. Debris has a way of being sucked up into the fuel line and getting hung up on the anti siphen valve at the tank fuel-cock.
Please ,this is tricky bisiness- go slow, be careful, be safe!
Roy & Laurie, S.F. Bay Area
'83 280, hardtop, single 305