psi3000

I have a LS motor in my 70 and have been looking and looking on google and LS1tech and can not find an answer. Where should i be wiring the relay for my aftermarket fuel pump to from the steering column? Would the positive to the HEI distributor do? Also i read something about needing a MSD box but got lost in what they were saying on that forum. Do i need a MSD box for some reason?

Project GatTagO

iTrader: (7)

The best place to get power for the fuel pump is directly from the battery. You want a constant 12-14 volts going to the pump.

If you are going to use the EFI, you do not need an MSD box.

You should consult the 100,567,356,235 GM a-body build threads for details.

Andrew

psi3000

Sorry, I meant for the switch to turn the pump on, not the power source .

psi3000

And how do I find the numbered mentioned threads?

bczee

iTrader: (12)

You will need 4 wires for the Relay..

1) Battery 12+V (term 30)
2) Ground (Term 86)
3) Output to feed the Pump (Term 87)
4) Switched 12+ (generally if EFI, the PCM pin 9, to Relay Term 85)

If you have a carb.. #4 would be getting the 12+volt signal from some other source other than the PCM.. possibly a IGN hot with a Oil Pressure switch inline.

Some have use the HEI power wire, but make sure it turns on and off with the Key in the correct possition, removed and ballast resistor if one is there.

I hope this help and I reall correctly, getting late..zzzzzz

BC

Project GatTagO

iTrader: (7)

If you are going with the stock EFI, the relay will be activated by the computer.

Andrew

Project GatTagO

iTrader: (7)

https://ls1tech.com/forums/conversio...2-gm-body.html

psi3000

yeh but the numbers you referenced, 100,567,356,235, what do they mean and how can i find them?

1964SS

iTrader: (1)

By clicking the link he just posted for you above.

psi3000

What are those numbers in other words? I am fully aware of the chevelle build threads you have posted a link to. But what is 100? What is 567? Ect...