Fuel pump wiring - extra relay?

[70XIN]

Hi guys,

I made another thread a few weeks back - but i have a working multimeter now, so most of what i said is just confusing.



Anywho, i'm trying to put a honda motor into an AE86 - the "FC" (fuel control) wire of this motor outputs voltage to switch the fuel pump relay, whereas an AE86 COR/relay is activated (or held open i guess) by a ground(?).

Is it okay / good practice to just make a 'negative switching relay' () , and have this run from my ECU to the standard AE86 fuel pump relay? Or is having a relay switching a relay stupid?

I know i could just run a relay straight to the fuel pump and bypass everthing, but i'd like to keep it all safe/factory-ish.

[Hen may possibly be a nut]

You can use a relay to convert your ECU signal from positive to negative (exactly what is shown in the bottom two diagrams you linked to). No problem doing that other than it's not as neat with the extra wires and extra relay.

Another option is to ditch the stock COR and make up your own using two normal relays (one for STA and one for ECU signal). May end up just as messy though.

Hen

[70XIN]

The less i have to do, the less i can screw up haha - i won't be sad about having another relay there anyway. Just wanted to know it's safe thanks!

[Matt]

Run the fc honda pin to the sta input on your toyota relay... Just make sure the existing wire is cut so you dont continually send a starter signal to the ecu and the starter motor