323z

So the title says it all. I need help with wiring a Magnafuel 4303 w/Hobbs switch and a Magnafuel relay MP-1025.
I have it mounted/fuel lines/power and ground lines ran to the engine bay(8 gauge)

Is this a right way to wire this up? Thanks in advance.

tennerv8

iTrader: (7)

I used the hobbs for grounding the relay, instead of powering it.

323z

Thanks, I want to say I have read that other members have also wired the hobbs to the ground.

So in my diagram, I would wire the orange 14 gauge from the magnafuel mp-1025 relay right to the pos side on the battery and the hobbs gets wired in between the ground on the relay? does that sound right.

007FJ

iTrader: (28)

Switched power to the coil of the relay...ground thru the hobbs. How I did it.

svslow

I always ground the relays.

323z

So should I move the hobbs to the ground then? getting confused here lol.

spray280

iTrader: (5)

323z

Thanks spray, wanted to revise this encase someone else is looking for the info.

I was on the phone with magnafuel and holley.
As per the instructions from the MF tech guy, I am going to wire the MF relay close to the fuel pump.

Blue wire on relay to positive on fuel pump, the red wire on the relay goes to the 8 gauge to the battery, black to ground, and orange wire from relay to engine bay to the holley efi's inputs/outputs.

Instead of going through the hobbs switch(connected to the orange wire) I will use 1 of the 4 inputs/outputs to control the magnafuel 4303 to come on.

Old Geezer

iTrader: (3)

I'd check the pump amp draw before I used 14 16 ga wire for anything except the Hobbs pulling the relay to ground.......

323z

I agree, Old Geezer but said 14 gauge is on a 30/40 amp relay, that's made for the FP.

The 14 gauge wiring is on the Magnafuel relay, part # MP-1025.

Main power is 8 gauge from battery to 10 gauge on relay then from relay to fuel pump with the blue 14 gauge wire. The 14 gauge orange is lengthened and ran to the holley 's efi to the inputs/outputs.

Old Geezer

iTrader: (3)

Ok....The 14 ga is still the limiting part of the pump feed. why start w/ 14, then change to 10??

323z

Old Geezer,
Sorry maybe I am not saying/explaining it right.

The Magnafuel fuel pump relay part # MP-1025. has 3# 14 gauge wires. and 1# 10 gauge.
The 10 gauge is where 12+ power is going into(from an 8 gauge from battery)
The 10 gauge with 12+ goes into an 30/40 amp relay.
A 12 inch 14 gauge wire(blue wire) from relay is ran to the +positive pole on the 4303.

Normally I would agree with you on not running 14 gauge wiring. But this is magnafuel's fuel pump and wiring relay and how magnafuels's tech department says hook it up. (from 2 tech's that have the same set up)

I am not telling you, you are wrong geezer. But since this fuelpump and relay are from the same company and meant for each-other. I will listen to what the manufacture says to do first.