junito1

The fc has some type of bulk head connector. Can these be reused? I was hoping I could just get rid of old wire/connection on the factory style bunkhead connector , scrape off that epoxy to solder 10ga wire directly to it and lay new epoxy over it to avoid using new buklhead connectors?

Has anyone.tried this.

TDIT

I'm looking at a similar problem currently. My female plug (coming from the wiring harness) is being heated and damaged by age and extra power draw (two internal pumps.) I can't find a new connector for the wiring harness, so am going to be forced to do what you are proposing. If anyone knows where I can get a new plug to suit the pump head male, please let me know as it's only a matter of time before I have to grind the plastic away and make a new connection.

clokker

iTrader: (2)

Here's how Aaron Cake did it.

junito1

Can the factory, already existing, bulkhead connectors be used? Has anyone done this? I would like to avoid drilling and/or removing the factory bulkhead connectors.

RotaryEvolution

iTrader: (30)

yes, the factory bulkheads are fine. use the factory wire cut back a few inches from the bulkhead and use the original stud inside. i have never seen a series 4 bulkhead burn up on any pump yet. S5/FD on the other hand... meltdown!

the S4 is the best factory pump housing which requires almost no modification for even the highest horsepower builds. but keep in mind it is a little too short for a series 5 tank, it can be extended and clamped down in the correct position as well as the s5 fuel sender swapped over with ring terminals added.

junito1

Nice! But I would like to avoid having a 10ga wire joined to factory size wire.(16-14 ga?) Would this not create some kinda of "choke point" for amps or something?

What I'm doing is extending the haltech trigger signal and (grey)switch wires from original haltech fuel pump relay to a new relay and running 10ga from batt. , to 10ga fuse holder, to relay , to bulkhead, from bulk head(in tank) to pump connector. .all 10ga wire is the plan.

RotaryEvolution

iTrader: (30)

it creates a bottleneck but it isn't as dramatic as some people make it sound. i've run pumps with the factory 14gauge? wires numerous times without any problems, in some cases running 17v+ @450-500whp single pump through that junction and not had it show any problems.

junito1

My fuel pump wires got really hot at the dyno. And I was loosing fuel press at only 7psi inhigh rpms. When I got home I went to town on her and found it was due to loose clamps on the pump/cradle in-tank hose which already had a hose to big for it. Blah. Anyways I went out for 7 psi tune for this reason, find all the bugs before going any further.

Now that I know of the issue I'm going to try and keep all 10ga wire aside from the bulkhead connector. I already got a good in tank hose for the loose or swollen old one.

Has anyone ever scraped the epoxy of the factory bulkhead connectors?

RotaryEvolution

iTrader: (30)

heat it with a heat gun on low and chisel it out with a small screwdriver.

you can get to the topside but unfortunately i semi recall it being a mushroom press fit for the wire loop on the top. best to just get a few bulkheads, drill the holes to size and get rid of the old stuff.

the only pumps i have run into issues with are the denso supra pumps, they eat up a lot of amps under a load and i usually have to run dual relays on them.

wthdidusay82

iTrader: (15)

I'm gonna have to do all this to rewire my walbro 255lph I'm assuming

Rotary > Pistons

jjwalker

Amperage is not like water and doesn't see choke points. It only sees total resistance from positive to negative (or Negative to positive if you want to be technical).

Let me use a real world example i run into at work sometimes...

Lets say, I have two 500 watt amplifiers to install. I can do two things...

1) run two 8ga wires at a maximum of 16ft or...
2) run a single 4 gauge wire, a maximum of 16ft and split off to 2 8 gauge wires near the amplifiers.

Option 2 offers a much lower cost, and less labor for my customer. Current handling of a wire (circuit) is determined by the entire DC resistance of the complete circuit itself. Option 1 and 2 will have nearly the same resistance, so which one would you choose? Option 1 requires much more labor and cost, and option 2 is cheaper and less labor for the same thing.

Make sense?

clokker

iTrader: (2)

Out of curiosity, why would the labor/material cost be much lower for option #1?

jjwalker

option 2 is cheaper, not option 1.

clokker

iTrader: (2)

Yeah, brain fart...but same question.
Why is option #2 cheaper?

fc323

It seems because one wire is cheaper than two..i think...even though 4 gauge wire is pretty expensive ..

junito1

Could someone explain why my fuel pump 12v and ground wires are getting hot?

This is the problem I'm trying to fix. And if people say the wire needs to be upraded to a bigger gauge, why only run the wire 3/4 of the way? Idk. I'm stuck on running it all the way to pump.

I run an aeromotive stealth 340 in tank for those wondering.

RotaryEvolution

iTrader: (30)

have you checked the ground from the tank to chassis? try adding a second ground also.

jjwalker

A single 4ga wire is cheaper than 2 separate 8ga wires of the same length. Labor is less because I spend less time penetrating the firewall and tucking the power wire underneath panels. Running 2 8ga wires takes about 1.5x longer than running a single 4ga.

wthdidusay82

iTrader: (15)

Why can't any of y'all live near me, I'm pretty nervous about rewiring my walbro 255 lph.

I'll get it done though

Rotary > Pistons

jjwalker

12v is not scary. Relax, it only bites when your hands are sweaty.

wthdidusay82

iTrader: (15)

Its been really hot here so ill probably be sweating

Rotary > Pistons

TDIT

Thanks mate - that gives some great ideas. I'm thinking plastic m12 bolts which I'll drill out to allow 40amp wires to go through - fuel proof apoxy sealed top and bottom - for power and earth for the pumps. that way I can keep the original plug for the fuel sender without having to rewire it or worry about it heating up (running two walbro internals - without a relay - the sparky that did it was a dick.(!)

Thanks to everyone else who offered ideas and suggestions. Very much appreciated! I'll post pics of the results on my 20B thread.

Cheers!

TDIT

You can just feel 48 with dry hands. 12 is no drama - but don't put the terminals to your tongue!

TDIT

I should note my battery is boot mounted so it doesn't have to travel fa. Still, I'm not a sparky but even I would have put a relay in place. (The above setup has lasted two years, so it can't have been getting 'that' hot. But now that there's a suspect connection the resistance has gone up, as has the heat - hence the deforming plug.)

RotaryEvolution

iTrader: (30)

epoxy won't work, get the proper bulkhead junctions. if it's not 100% sealed it WILL leak fuel.

even wires run through the top of the tank will carry fuel and vapors through into the cabin. the tank is pressurized when it heats up. it will work as a temporary solution but not a permanent one.