S13 pump hardwire specific question - earth?

[leonl]

Hey guys,

I Hard wired my fuel pump with a relay kit without any issues, relay to power and chassis earth, then trigger wire on chassis side and then another to pump power side. The pump primes and then stops like it always has, car starts and runs so all seems to be fine and done correctly.

my question is some guides online say to cut and extend the earth wire on the pump side and earth this wire to the chassis instead.

some guides don’t say to do this.

can anyone provide information on this? Any gains from earthing it to chassis? Any reasons it’s a must do? Does it matter either way?

cheers

[green_rs13]

if the original wire is good and has a good ground that it should be ok.

[leonl]

So is it worth just earthing it in the boot anyway just incase?

[m17ch]

86 and 85 should be connected to your existing pump wiring (positive and negative).
30 to a new thicker positive wire going to your battery plus terminal and 87 to a new thicker negative wire grounded to your chassis.


according to the star-point grounding principle you should not have more than one wire going to your battery terminal, so the fuel pump should be grounded at the chassis.
https://www.youtube.com/watch?v=WIDM66_iM-Y

[leonl]

I see people ground it at the fuel pump cover but believe that bolt goes into a plastic insert so I’ll extend the wire and earth it somewhere else

[6terras]

I grounded my relay to the chassis. My relay is on the right hand side of the boot behind the wheel arch. there was already a DIY earth stud fitted by me for an audio amp. Works fine

[leonl]

I grounded my relay to the chassis. My relay is on the right hand side of the boot behind the wheel arch. there was already a DIY earth stud fitted by me for an audio amp. Works fine

My relay is grounded,
I’m talking about the red/blue wire from the actual pump that some people also earth

[pointz]

After seeing the pictures of your wiring and how good a condition they are in I don't know why you even really needed to hardwire tbh.

I agree with green_rs13

[skyshack]

The rear body ground point is near the tailgate latch and relays that hide there.