Mechanical fuel pump to electrical

[jobofly]

Hey guys I bought a new marine rated carter electric fuel pump. I want to wire it in properly through the oil pressure switch. Problem is that I can't find the oil pressure switch on my motor. I have. 1985 omc Chevy 350 v8. Can you guys give me an idea where this thing would be located?

Thanks

 

[thumpar]

Re: Mechanical fuel pump to electrical

You will need to get an oil pressure switch. The oil pressure sensor that you have it not meant for controlling an electric fuel pump so you will need to add the pressure switch.

 

[jobofly]

Re: Mechanical fuel pump to electrical

How do I add a oil pressure switch to it?

 

[Bondo]

Re: Mechanical fuel pump to electrical

How do I add a oil pressure switch to it?

Ayuh,.... Find the oil pressure sender, which is either beside the distributor, or down low portside by the oil filter,...

Pull it, 'n add a "T", 'n put yer oil pressure switch on the other side of the "T",...

Then, from the Ignition circuit, run a wire through yer switch to the fuel pump,...

Also, run another wire from the outside tiny post on the starter's solenoid, to the fuel pump,...

That way, while yer Crankin' the motor, the fuel pump gets Power from the starter, 'n when it Starts, it gets Power from the Ignition,...

 

[jobofly]

Re: Mechanical fuel pump to electrical

Can I use an oil pressure switch from a auto parts store?

 

[Bondo]

Re: Mechanical fuel pump to electrical

Can I use an oil pressure switch from a auto parts store?

Ayuh,... So long as it closes at 'bout 3/5psi, 'n fits the port,.... Sure,...

 

[mopar_nocar]

Re: Mechanical fuel pump to electrical

Can I use an oil pressure switch from a auto parts store?

Short answer: YES

Much longer answer:

There's a number of ways to do this. I would use a relay to run the fuel pump and let the oil pressure switch ground the relay. I'd also have a start relay that was wired in, but only is energized by the start circuit. A bit more wiring and expense, but better electrical distribution and, in my humble opinion, elegant. If interested, I can help you with the wiring.

Oil pressure switch standard parts# PS133T
2X 30 Amp Relay dorman part # 84601

That switch can be used to wire the fuel pump w/o a relay as stated in previous the posts. (This is the reason for the bold)The middle post would be to light a warning light, the two that are parallel to each other complete a circuit when oil pressure is 7lbs or higher.

The plumbing (T and what have you) are up to you, but dodge trucks of the mid 80s have a piece that has two ports on it and would screw into the brand X block you have and save some space & money and allow you to still use your factory oil pressure switch. I imagine that most Pick & Pull JY would basically give you the piece.

Good luck.
sb

 

[Bt Doctur]

Re: Mechanical fuel pump to electrical

Here or by the dist where the sender is.

Use a relay to power the fuel pump. Have found that certain pumps if they jam slightly will draw more current than the switch can handel
standard cube rely works.

 

[jobofly]

Re: Mechanical fuel pump to electrical

Short answer: YES

Much longer answer:

There's a number of ways to do this. I would use a relay to run the fuel pump and let the oil pressure switch ground the relay. I'd also have a start relay that was wired in, but only is energized by the start circuit. A bit more wiring and expense, but better electrical distribution and, in my humble opinion, elegant. If interested, I can help you with the wiring.

Oil pressure switch standard parts# PS133T
2X 30 Amp Relay dorman part # 84601

That switch can be used to wire the fuel pump w/o a relay as stated in previous the posts. (This is the reason for the bold)The middle post would be to light a warning light, the two that are parallel to each other complete a circuit when oil pressure is 7lbs or higher.

The plumbing (T and what have you) are up to you, but dodge trucks of the mid 80s have a piece that has two ports on it and would screw into the brand X block you have and save some space & money and allow you to still use your factory oil pressure switch. I imagine that most Pick & Pull JY would basically give you the piece.

Good luck.
sb

I was going to use this diagram to wire it properly. Does this look right to you?

 

[jobofly]

Re: Mechanical fuel pump to electrical



Actually I think this is the right diagram.

 

[Bt Doctur]

Re: Mechanical fuel pump to electrical

jobofly, That one will work too but I`d use the one with the relay. Less chance of burning the contacts out

 

[jobofly]

Re: Mechanical fuel pump to electrical

Thanks for the tips everyone

 

[jobofly]

Re: Mechanical fuel pump to electrical

One more question. What size wire should I use for all of this?

 

[mopar_nocar]

Re: Mechanical fuel pump to electrical

One more question. What size wire should I use for all of this?

I'd use 10ga to feed the relay. 14ga for the ground & the switch and 12ga to supply the fuel pump. I've used lighter stuff for this, but don't really feel comfortable with it.

sb

 

[bruceb58]

Re: Mechanical fuel pump to electrical

14 would be plenty big. I bet it even says this in the instructions.