Obs 7.3 efuel DIY wiring diagram

[F350stroker]

I have searched up and down on the internet for a straightforward way to build a wiring harness. I wanted one with an oil pressure safety switch and a way to run the pump on a timer so if you keep the key on and don’t start the truck that the pump quits without oil pressure. And also if a fuel line was severed in a collision that it would quit pumping when the engine dies and there is no oil pressure. I found lots of ideas but nothing very solid. I drew this up and would like to have some criticism if there needs to be some as I am not at all proficient with wiring. I want to build my own instead of buying driven diesels because I’m in Canada and by the time I get it up here it will be around 250 bucks. So here goes, see what you guys think and I haven’t built it yet so let’s here it if I should change anything before i build it.

 

[gnxtc2]

Not going to work as you want it to.

The GPR has constant positive 12v power to it when you turn the key on. The PCM grounds the relay.

You can add the oil pressure switch but you won't have any power to the pump until oil pressure is built. There is a NO/NC oil pressure but those fail. I had a NO/NC oil pressure switch and it was giving me issues and eventually eliminated it.

Just control the relay with the fuel bowl heater wire.

Billy T.
[email protected]

 

[F350stroker]

Thanks for the input, if I use the side of the gor that powers the glow plugs doesn’t that go dead after the plugs are pre heated ? Then once the oil pressure is up would the fuel bowl constant circuit take over to keep the power going to the pump ?


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[Copperhead]

I want to build my own instead of buying driven diesels because I’m in Canada and by the time I get it up here it will be around 250 bucks.

Seriously,........ 250 bucks,....by the time you figure in shipping,.. for this ,... ?
https://www.strictlydiesel.com/p-2804-obs-fuel-pump-harness.aspx

Come on,...


I've shipped things north of the border several times and long as they use USPS,....instead of Fed-Ex or UPS,...it shouldn't be nowhere near that much.


FWIW,....
I used this harness in my DIY Electric Fuel Conversion on my 97,.....and I was really impressed with the quality and ease on installation.

Top notch piece.

 

[jschildm]

I installed an inertia switch with my kit, if you are concerned about shutting down due to an impact. This way, it doesn't take oil pressure to start the pump running, but it shuts off if you get in a pickle.

 

[m_j]

the only part of the Driven kit you need is the timer.
I trust the oil pressure switch more then an inertia switch.
the relays and fuses can be inserted in to the factory underhood fuse/relay box for a factory look.

 

[jschildm]

the only part of the Driven kit you need is the timer.
I trust the oil pressure switch more then an inertia switch.
the relays and fuses can be inserted in to the factory underhood fuse/relay box for a factory look.

I haven't been in an accident, but I hit a deer dead center and the impact was enough to trip the inertia switch, so I guess i have some decent faith in mine. Maybe a roll or something else would be a different story.

 

[F350stroker]

Seriously,........ 250 bucks,....by the time you figure in shipping,.. for this ,... ?

https://www.strictlydiesel.com/p-2804-obs-fuel-pump-harness.aspx



Come on,...





I've shipped things north of the border several times and long as they use USPS,....instead of Fed-Ex or UPS,...it shouldn't be nowhere near that much.





FWIW,....

I used this harness in my DIY Electric Fuel Conversion on my 97,.....and I was really impressed with the quality and ease on installation.



Top notch piece.

The harness is 129 bucks and I did go right to the shopping cart check out and the shipping quote with my address was 48 bucks so that’s $177 x 30 percent when using a visa exchange (or close to it) and pardon me it’s $230 bucks Canadian. Still hard to justify.


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[CANbus]

Not going to work as you want it to.

The GPR has constant positive 12v power to it when you turn the key on. The PCM grounds the relay.

You can add the oil pressure switch but you won't have any power to the pump until oil pressure is built. There is a NO/NC oil pressure but those fail. I had a NO/NC oil pressure switch and it was giving me issues and eventually eliminated it.

Just control the relay with the fuel bowl heater wire.

Billy T.
[email protected]

Do you recall which NO/NC oil pressure switch you were using? I'm looking at doing this and keeping it looking as factory as possible.

 

[gnxtc2]

Don't recall the exact part number but it was made by Standard. I have since removed it as it was problematic and have no issues running without it.

Billy T.
[email protected]

 

[CANbus]

Don't recall the exact part number but it was made by Standard. I have since removed it as it was problematic and have no issues running without it.

Billy T.
[email protected]

Thanks. I was looking at the Holley version. Now looking into a timer setup that has a 3-second prime and does away with the oil pressure switch.

 

[Gnathv]

Will a 3 second prime work? Doesn’t the excess go into return lines back to tank?

 

[gnxtc2]

Just hook up a relay controlled by the fuel heater wire and be done with it. Don't over complicate the install. Keep it simple.

Billy T.
[email protected]

 

[CANbus]

Will a 3 second prime work? Doesn’t the excess go into return lines back to tank?

Return goes to the tank. Would like a prime that auto stops in case I need to leave the key on.

Just hook up a relay controlled by the fuel heater wire and be done with it. Don't over complicate the install. Keep it simple.

Billy T.
[email protected]

Does the heater wire stay hot all of the time? I thought it was temperature dependent.

 

[gnxtc2]

Return goes to the tank. Would like a prime that auto stops in case I need to leave the key on.


Does the heater wire stay hot all of the time? I thought it was temperature dependent.

Key on - hot all the time. Key off - turns off.