hey guys and gals,hope everyone was good this year...and got what they wanted for christmas! was wondering if someone could explain to me how a sending unit(in the tank)works.i have one from a 69.5 mav with a single electric connection,and a 73 with two connections.i'm using the wiring harness out of my old 69.5 and was going to use the 73 tank.is there any way to fanaggle the wiring to do this?,or is the other electric clip on there for a reason?,or am i better off finding a later harness.i am using the complete wiring harness from the 69.5 front and back.any help in explaining this is very much appreciated. happy holidays...chuck.
The single wire goes to the fuel gauge and receives its ground through the tank itself, which in turned is grounded to the chassis. The 2 wire system has one of the wires as ground and loops it through the sending unit. All you have to do is make sure the sending unit, where it touches the tank, is clean, and the tank is grounded to the chassis. Then make sure you hook the single wire to the wire which goes up to the gauge. Its easy to figure out which wire that is. Just ground them 1 at a time. The wire that makes the gauge deflect to full is the one you want.
Hey Chuck...I believe there is a positive/negative...male/ female plug on that sending unit...your 691/2 wire should plug to that sending unit..either the male or female plug, whichever fits. run a wire from the other plug and ground it on the chassis...I think that rubber gasket is gonna keep you from getting a good ground from the unit itself.
The sending unit gets a ground through the locking ring that holds it in the tank. It is metal to metal contact. The other side has the O ring. On the 2 wire set up, The wire your not going to use is already a ground so you dont need to do anything with it unless you want to extend it out and ground it directly to the tank. Even if you do, I would still run another to the chassis. You can never have enough ground.
dennis and rick,thanks guys for the info,it is highly appreciated. will be trying it in another week or so.dennis,almost forgot...is there a chance of me blowing myself up,or the gauge just won't work if i put the wires on backwards?just curious...never tried it befor.thank you...chuck.
There's always a chance of blowing up but not by playing with these wires. The gas gauge gets power directly on one side through the voltage regulator, mounted on the back of the dash panel. The other wire is looking for a ground, and this is the wire your playing with. The sending unit puts some resistance in the ground wire to make the gauge read according to how much fuel is in the tank. So even if you grounded them to the neg terminal of the battery, all you'll do is make the gas gauge peg on full.
