FJ40 Fuel pump wire (1 Viewer)

[Armordave]

I noticed that the truck I got recently has a haphazardly "installed" wire that (runs all over the place) from an electric fuel pump they put in to a random spot on the down side of the fuse box. Aside from it being a terrible installation, where should that pump be getting its power from? I am assuming the ignition switch but where exactly, if someone can post a photo or some information. I have wiring diagrams but they don't show an aftermarket electric fuel pump set-up. I will research why they went to electric and if I can put it back to original.

 

[Dynosoar]

A fuel pump should be powered by the battery and switched via relay from the ignition.

Dyno

 

[numby]

I'd do like Dynosoar sez but I'd add an inline switch between the ignition connection and the relay as a secondary kill switch. DO NOT use a switch only. You want the fuel pump to stop pumping whenever the key is turned off.

 

[Solace in Solitude]

I'd do like Dynosoar sez but I'd add an inline switch between the ignition connection and the relay as a secondary kill switch. DO NOT use a switch only. You want the fuel pump to stop pumping whenever the key is turned off.

To build on @numby's suggestion... I have posted this previously... I'll just quote it here

"A note of caution... with an electric fuel pump, you really should ensure the pump is disabled, in the event of a loss of oil pressure... like the truck rolls and the engine dies... otherwise, fuel keeps pumping...

You can easily protect yourself by installing:

1. a T between your oil filter and your oil pressure sender. I used https://www.amazon.com/Squirrelly-Pressure-Sending-Adapter-Female/dp/B00QXK0QSW

2. Installing an oil pressure safety switch (OPSS). I used this one. It kills power to my fuel pumps, when oil pressure falls below ( or equal to IIRC) 2psi... but, allows the pump to run, when starter is engaged (without oil pressure). https://www.amazon.com/Carter-A68301-Engine-Pressure-Switch/dp/B000CSWR10

Three wires:

1. I = ignition
2. S = starter
3. P = Pump

"I" carries power to OPSS

OPSS “P” forwards power to pump, IF oil pressure is > 2psi OR starter (OPSS “S”) is engaged."

 

[Armordave]

So I got in the parts suggested by Solice in Solitude andI’m going to install them today. What pin in the back of the ignition switch does the “I” wire connect to? Also on this fitting https://www.amazon.com/Squirrelly-Pressure-Sending-Adapter-Female/dp/B00QXK0QSW?tag=ihco-20 which port does the OPSSgo into (end or side)? I have a mechanical oil presure lien to go into the other one.

 

[Solace in Solitude]

Squirrelly side port is for the OPSS.

You want the OPSS-I to always have power, when the ignition is "on"... so, whatever wire is hot, when the ignition is 'on".