Wiring a fuel gauge to ignition circuit

[Slacker411]

Can anyone give me advise on wiring a fuel gauge to the ignition circuit so the gauge only reads when the key is turned? I have a 1978 Mecury V-1500 150hp outboard. I have fuel sender with ground to (-) battery terminal, and (S) sender wire going to the (S) terminal on my gauge. I need to figure out where I need to hook up the (+) 12v red wire to the ignition circuit.

 

[MH Hawker]

Re: Wiring a fuel gauge to ignition circuit

The purple wire is the switched wire from the key switch.

 

[Slacker411]

Re: Wiring a fuel gauge to ignition circuit

Thanks a lot. The purple wire worked great and I now have a working fuel gauge. One thing about my setup is that I cannot see any fuses anywhere from my battery to the wiring harness on the motor. Isn't there supposed to be at least a fuse on the positive 12v cable from battery going to the motor?

 

[alldodge]

Re: Wiring a fuel gauge to ignition circuit

Thanks a lot. The purple wire worked great and I now have a working fuel gauge. One thing about my setup is that I cannot see any fuses anywhere from my battery to the wiring harness on the motor. Isn't there supposed to be at least a fuse on the positive 12v cable from battery going to the motor?

There is a 50amp push type breaker on the engine (red button). There is also usually a 20amp fuse behind the dash, an inline type and many cases can be over looked