Wiring Question…. How to make a wire hot only when the ignition is on?

[85GTKid]

The way I have my old cfi electric fuel pump wired for my carb setup isn’t working so well. When I turn the key on the pump turns on and I litsten to the pump. When I turn on the blinkers with each blink the pump will be quieter as if power is being taken away to the blinkers. When I turn my headlights on it’s the same thing but it a constant drain on its power. This cant be good for the pump or performance. How would I make a wire that doesn’t share power with anything while the key is on? I hope I don’t sound too confusing.

 

[Kiknads]

you could use the key-on wire to power a relay which in turn would close a circuit from the battery to your fuel pump

 

[TIMMY2734]

Hows your alternator working?

 

[85GTKid]

Hows your alternator working?

i the engine was nut running when i did these test....anyway its good. Bat was at 12 something with car off and 14 something with car on.

 

[HISSIN50]

why would you turn the key to on, and have the blinkers or headlights on?
kiknads is right. i would use blocking diodes if wiring multiple power sources, if you decide to do that).

good luck.

 

[85GTKid]

why would you turn the key to on, and have the blinkers or headlights on?
kiknads is right. i would use blocking diodes if wiring multiple power sources, if you decide to do that).

good luck.

To see if power is being taken away from the pump while the car is actually running.

 

[HISSIN50]

To see if power is being taken away from the pump while the car is actually running.

ok, sorry i must have misunderstood. you cant compare if "power is being taken away" with non running motor vs a running motor. while running, the alternator should be keeping up. remember, the pump actually flows at different rates depending upon how many volts are comin out of the charging system. it is not a real big deal or fuel circuits would have regulators to maintain a constant flow of juice.

so i think i missed something with how you are checking this. again, sorry for the confusion.