another electrical question

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whitey

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I'm getting close to starting the car, I'm finishing up the fuel lines. I have a Holley electrical pumpand I need switched power for my pump and some gauges. Where is a good source for switched power? What wire/fuse, where?
 
Switched power should come from ignition switch. That is protected by the fusable link and can power the gauges . From there it should signal a relay that carries hiher amps to the pump. That feed can come from before the fusable link and should be fused before the relay.
 
I talked to a long time friend who has a 79 TRans am with a BB. he has his wired directly to the ignition with a 25 amp fuse right there.
 
whitey said:
I talked to a long time friend who has a 79 TRans am with a BB. he has his wired directly to the ignition with a 25 amp fuse right there.
Click to expand...

Maybe your friend didn't have a forum where he could ask what is the proper way to do things. Wire it directly to the battery if you want.
FIREbird LOL
 
the holley pumps usually only require a 15a draw. i would run the gauges the back of the fuse box where there are ignitiuon hot spade tabs to add on to. the fuel pump can go there as well, but run a relay with it or at least an inline fuse.
 
Don't you really need an inertial switch of some kind, in order to be safe? Otherwise, in the event of an accident, the electric fuel pump can continue to run and feed any fire that may get started.
 
This is where modern technology is fun.. There is some good info about fuel pump circuits on google images. you could also pick up an impact sensor from a car at a yard to work into your diagram. my old ranger had a little magnetic ball socket type cut off for the fuel pump located inside on the passenger firewall/floorboard. some cars have them in the trunk. cool little safety feature, but also kinda annoying if you hit a speedbump really fast.

google search fuel pump inertia switch..
 
whitey said:
I guess my question to be more specific, what wire in the column harness can I tap into?
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I second the comment to use a relay to control the fuel pump. 15 amps is a tremendous of amperage to draw through an allready taxed aging wiring harness. To pull that much more amperage through it your just asking for a fire. Your friend got real lucky he didn't have a roasted Firebird. A cutoff switch like either style that 63Dartman ot Player1up mentioned is also a very good item cause you just never know when an accident can happen.

To answer the question about which wire specifically. Get a test light and see what fuses are hot only when the key is in the run position and that can be used to control the relay. The relay should be fed with a seperate wire of at least 12 gauge with a fuse going through the firewall directly to the battery.

I have a high powered stereo in my Cuda and the 6 Ga. power wire I ran for it inside was a perfect place to also draw power for my fuel pump.

Good luck
 
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