Has anyone rewired the fuel pump circut?

JFairman · 10-20-2009, 12:50 PM

I'm looking for ideas here.
The %#@**&!! yellow overboost relay and all the wiring that has anything to do with it is coming out of my car today.

I have the rear console electrical console all apart for the first time and there is melted insulation and burnt wires under there from the rubber plug socket for the yellow relay.
I don't trust that overboost circut anymore, it only strands me on the side of the road repetitively, so it's all coming out.

I remember somebody else got fed up with it and stripped all the nonsense out and rewired things so the fuel pumps work without the overboost circut.
There's a mess of little wires from the yellow relay and I don't know which ones to solder together and which ones to cut and tape the ends over and forget about.

Has anyone done this before and could you please tell me how you did it?

thanks,
Jim

mark houghton · 10-20-2009, 02:01 PM

Quote:

Originally Posted by JFairman

I'm looking for ideas here.
The %#@**&!! yellow overboost relay and all the wiring that has anything to do with it is coming out of my car today.

I have the rear console electrical console all apart for the first time and there is melted insulation and burnt wires under there from the rubber plug socket for the yellow relay.
I don't trust that overboost circut anymore, it only strands me on the side of the road repetitively, so it's all coming out.

I remember somebody else got fed up with it and stripped all the nonsense out and rewired things so the fuel pumps work without the overboost circut.
There's a mess of little wires from the yellow relay and I don't know which ones to solder together and which ones to cut and tape the ends over and forget about.

Has anyone done this before and could you please tell me how you did it?

thanks,
Jim

I believe 930Rocket is your man.

RarlyL8 · RarlyL8's Garage

You may not wish to do it this way but I have my pumps wired to come on when the key is in the 2nd position. Just run a fused line off a switchable 12V source, same as the ignition.

A930Rocket · 10-20-2009, 05:46 PM

I wired my two red fuel pump relays so that when I turned on the ignition, the fuel pumps turn on. This was done by adding an inertia switch to the grounds going to the red relays. Any inertia switch will work. I just happened to use a Ford Mustang one.

If you haven't done the Lee Rice electrical upgrade, now is a good time while you have all apart.

I also ran new wires to the fuel pumps for just in case one day....

JFairman · 10-20-2009, 09:10 PM

Thanks

Havn't torn into the front fuel pump relay sockets yet, just the back.
Is the skinny brown wire in your pic the the relay ground?

I should do the other modifications you mentioned too, my fuel pump fuse is always hot but the amperage draw with both pumps running is around normal.

Ken911 · 10-20-2009, 09:51 PM

that thing still not running?

JFairman · 04:40 PM

I've driven it and sometimes it's been semi reliable for a few days or so but i never drive it far because some intermittent electrical demon has possesed it for a while...

drmatera · 10-21-2009, 10:01 AM

I just finished removing that whole electrical "panel" back there. Losing all those factory relays and fuses with this Megasquirt project. The MS will fire my fuel pump relays now, but I haven't got that far yet so i'm no help at all. But I am always curious as to how others have done it.

JFairman · 10-21-2009, 10:14 AM

Here's how it looks right now...
If it actually runs after all this, it WILL be declared a national holiday.

..and the 2 melted yellow relay socket wires in the midle of the mess.

>i hate electrical problems.
wish me luck. . .

drmatera · 10-21-2009, 10:32 AM

on the surface it seems like a rats nest. But the wiring back there is actually somewhat simple once you lay it out.

A930Rocket · 10-21-2009, 02:26 PM

Once you add the inertia switch, you won't need any of that crap in the back. No relays, switches, etc.

I believe it is the thin brown wire, but check the wiring diagram.

mark houghton · 10-21-2009, 02:33 PM

Quote:

Originally Posted by JFairman

Here's how it looks right now...
If it actually runs after all this, it WILL be declared a national holiday.

..and the 2 melted yellow relay socket wires in the midle of the mess.

>i hate electrical problems.
wish me luck. . .

Wow, I like that! It's kind of an "art Deco" look, but would drive an electrician mad.

Quicksilver77 · 10-21-2009, 02:46 PM

LOL National Holiday!!! I am with you! I detest electrical problems... too abstract for my simple mind to wrap around!

Ken911 · 10-21-2009, 08:49 PM

I am shocked!! last time i saw your engine bay it looked like you could eat off of it. Best of luck when you get done you need to take a drive down sometime........Ken