Glad this thread turned out better than it looked last night. It got me thinking about my own Racetronix hotwire kit and the 340 LPH pump (both their factory 4th-gen replacement stuff), which had me asking questions that I won't be in a position to use answers on for a couple months yet (I'll save the questions for another time). Regardless, this thread has some good information despite the drama and I'm glad the conversation can keep going.

 

I got approved for the Racetronix user forum, asked there - why majority of installs just have the 2 wire harness and go without the BCWA bulkhead kit/harness - and here is some more info that might help people in the future, with pictures of some melted bulkhead plugs.
So to conclude here I want to say that the bulkhead connector harness I'm using really isn't needed, but they highly recommend it. Appears most people can get away without it just fine.
I can't get the wire back onto the fuel level unit with the friction washer unfortunately.. tried a couple other things to get it on there securely with no luck so I got a new aftermarket sending unit on the way, will post some new pics of it installed when it arrives

 

The issue with the Bulk-Head/ Pass-Through Electrical Connector that comes stock on many GM Vehicles (actually, most vehicles of any make)...
is that it is ONLY a 14A/ 15A Maximum Continuous Ampacity Connection.

If an In-Tank Electric Fuel-Pump is used... and requires near 15A (or more)...
The Bulk-Head is not going to last.
It will burn-up or melt!

All that needs to be done, is to swap-out the Bulk-Head for one with a higher-rated Ampacity.
25A/ 30A Bulk-Heads are readily available for GM Vehicles via Delphi or ACDelco.

In Post #45, I actually Posted all the Delphi Part-Numbers for a 25A Connection.

Not to mention that the Pinout of the Bulk-head can usually be changed in order to use 2 Terminals (for Power) instead of 1...
Most of you would never need more than a 50A Rated Connection.

As I have Posted many times...
The Third-Gen Pass-Through Electrical Connector (behind the Rear-Seats) can have the Ground Wire converted to a Power Wire...
For a 40A Rated Connection.

I personally always make use of Bulk-Head/ Pass-Through Electrical Connections.
I install them in many locations throughout the Vehicles that I build (as well as my own Vehicles).

I see no reason not to use them...
Bulk-Heads of some types are available up to 250A.

 

If you buy the complete Racetronix 340 pump assembly (4th gen bucket fully assembled) it will come with GT 280 connector and you'll need a hot wire kit specific to the 340 pump assembly. I ran into this with my car when I upsized from 255 to 340 pump. My old hot wire kit for the 255 LpH had the wrong kind of connector (Metri-Pack 150) and some other stuff was different too. I had to buy and modify another hot wire kit all over again for the 340 setup. My 340 LpH install is described in my build thread.

 

That is genius. I wish I had thought of that when I built my car!

I'd really like to undo what I did with my fuel pump pass thru. It's hokey. Do you know of a low-profile connector that I can purchase to build my own pass thru under the carpet? Nothing I've found is slim like stock. Maybe I should dig my old pass thru out of storage and give it a look with fresh eyes.

 

LOL!


I am sorry to say that I do not know of anything that is as Low-Profile as the Original Pass-Through.

For anyone who does not know what I am talking about:
-Remove the Ground Circuit Wire from the Pass-Through... Ground the Pump to the Vehicle.
-Take the now Unused Wire and also provide 12V Positive through it.
-Now Two Wires are providing 12V Positive at up to 20A each (combined 40A).

 

I found my original rear seat pass thru connector. Doesn't appear the terminals can be replaced unless I'm missing something. Although I did leave myself 5 inches of pigtail.

 

Don't replace the Terminals in the Pass-Through.

Just cut off the Ring-Terminal that is grounded to the Body.
Run a New Power Wire to it.

Then outside the Fuel Tank, Ground the Negative Wire of off the Fuel-Pump.
Connect the Two Power Wires to the Pump.

 

I've got the Racetronix 340 pump assembly (4th gen bucket fully assembled) and the corresponding hotwire kit. Have debated whether to just run the hotwire kit, or go through the trouble of using pieces of it and running it through the firewall, to the bulkhead connector by the pump, etc (similar to what you ended up doing Qwk). Leaving the hotwire kit in one piece definitely seems the easier route.

 

So to be clear on this, anyone using a larger than factory pump (even if it's just the Walboro 255/ Racetronix's 255) will cause eventual failure on the bulkhead or internal wiring due to them being to small? Just upgrading to a 255 pump with a "hotwire" kit seemed to be the standard way to upgrade to a more reliable pump on this forum which is what I have done. As much money and time I have in my pump setup, I guess I need to pull it back out and do the bulk head and internal harness then, would hate to have a failure due to that or worse. Crap.

 

It's six one way, half dozen the other. You've got to lay wires full length of car either way. I found the 4th gen Hot Wire kit to be awkward and ended up breaking it down to essentials and building back up again. It's designed to plug into a 4th gen car so it's got a connector you can't use, and other stuff you won't need. The wires run all over the place and it's not efficient layout for our cars. You'll see what I mean when you do the job.

I welded a stainless ground boss to the rear firewall. That helped a ton with wiring of grounds and cleaning up the harness.

 

I am running the Aeromotive 340 pump and the 4th gen. bulkhead connector, but the only wires that go through the bulkhead are the fuel level (2 wires), fuel pump trigger for the relay, and the ABS wheel sensors (4 wires). The larger gage power and ground drop down behind the tank and over to the right side spare tire well. There is a metal plug that was removed and replaced with a bulkhead grommet and the fuel pump relay, fuel pump fuse, and the starter solenoid are mounted to a plate and connected to a battery distribution block. This configuration has been flawless so far and removes any high amperage loads through the bulkhead connector.

 

Thanks Qwk. I didn't remember that part of your build thread offhand.

I'm also liking the idea of moving the large power passthrough to a location that's not as dependent on being thin due to carpet constraints (thanks soloc4! great idea.). If this is done, then a firewall pass-through connector could be used which supports the load and is larger in size.

 

On the topic of fuel lines. This thread points out the preferred (proper?) setup of having a return line from the rails, avoiding the C5 fuel filter style setup. I completely understand this if your engine needs more fuel than a factory C5 setup was intended to provide. What about those of us with semi-stock LS1 motors and fuel injectors?

I've got everything in boxes ready to go on, and am ready for a running car and less boxes come warm weather and time...
- Racetronix 340 LPH pump (4th gen replacement style)
- Racetronix hotwire kit for above pump
- Plastic? Nylon? (don't remember offhand) pump to fuel filter fittings and lines, mirroring another nice setup I've seen on this board
- C5 filter
- Pre-fabbed stainless line from filter to fuel rail
- 4th gen f-body fuel rail (no return line)

 

I think many people are in your boat. Good thing this is a hobby right? Always room for improvement => more working on the hobby.

 

Got a picture where you brought the connector thru?
All this time and I never though about running it to the rear. Another "wish I had done that" moment!

 

Alright guys, new sending unit and harness arrived.
However, trying to bench test the fuel level with multimeter to confirm but not able to get a reading on it. I was testing my stock unit this way and getting a solid reading. So just want to confirm here with you guys. Is the ground good and in the proper spot? The aftermarket sending unit has the ground tab next to the yellow bulkhead on inside lid, rather than on the hanger itself. How does this look to you? Confirmed the bulkhead wiring and harness are pinned correctly. Just want to make sure this is correct here before I put the filter sock on, install and stuff the tank back in! Feel like something may be off.




The harness that came with the aftermarket sending unit had the 2-wire ground going to the bulkhead and 1 wire going down to fuel pump.




EDIT : SOLVED . Aftermarket sending unit had the locking clip for bulkhead plug 180'd. I totally looked past it and snapped it back in as so, so things were backwards OOPS LOL

 

Here is the “Hot Wire” leads from the fuel tank. The grommet is a generic flanged grommet. I added the high amperage connector to make it easier to remove the tank, if it’s ever necessary.

 

Oh, i see, you don't use the stock exhaust routing. My exhaust pipe would cook that thing good. But you give me ideas! Thanks!

 

BajaDaze did the same thing when we installed his tank. He has the Hooker Blackheart true duel exhaust, we just ran the wires through an existing hole in the frame rail just above where you see mine. He also utilized the original metal plug with a hole drilled in it and sealed it with silicone.

 

The Under-Vehicle Wiring that I just looked at, appears to be done very nicely.

This would be a good time to mention that Wires routed under the Vehicle need to have significant attention payed...
In terms of ensuring that the Wiring does not interfere with Suspension/ other moving Components, Exhaust Components, as well as anything that would commonly be seen in the road that could damage the Wiring.

Essentially, it is always better to run Wiring into/ through the Cabin when possible.
Many years ago NHRA wanted the Main Positive Cable ran under certain Classes of Vehicles...
Now they pretty much require all Classes to have NO under-Vehicle Wiring.

...and Yes, of course short runs into/ out of the Fuel Tank/ Cell/ Fuel-Pump are permitted.
On the topic of Fuel-Systems...
It is also preferred to have a Fuel-Cell and Fuel-Lines inside of Vehicles where a Truck is separate from the Passenger Compartment.

 

I forgot to mention that this car will have a full pan diffuser from the rear of the tires back and enclose the center exhaust. In essence, the wires you see will be “inside”. There will be no moving parts, heat, or road debris in this area, but your concerns are valid if this was any other 3rd gen.

 

I'm trying to throw together a 1-pager for this but have a few questions...

External connector: What cable seals are used with 13527865? I can't find a drawing for that part.

Also, when I go to the bulkhead part drawing it calls out mating connector 15326631 instead, which in turn calls out cable seal 15366067 with 6.35 mm OD. However, I thought GT 280 were typically 5.8 mm cavity? I can't clear up the answers on my own without real line drawings. And I can't find any info on that cable seal to know what is the cable range, and other similar p/n's in that family of seals. It's not a seal I've run across yet in my long list of seals!

Internal connector: Drawing for 13517799 calls out CPA 12092873. You listed CPA 12052834. Are those interchangeable? I can't find a line drawing for 12052834 to examine the differences.

 

I just triple checked all the Part Numbers that I Posted with my Data-Sheets in my Filing-Cabinets.
Everything I posted was intended.

The External Connector #13527865 is an "Ethanol Safe" 4-Way GT-280 Connector... It uses the regular GT-280 Cable-Seals and Terminals.
The #15326631 External Connector is the "Standard" 4-Way GT-280 Connector... It can be used instead of the #13527865 "Ethanol Safe" Connector, if you wish.
Both versions of the Connector are supposed to use the same Cable-Seals and Terminals.

The CPA for the Internal Connector originally used Part #12092873 (a Red Color variant) which is discontinued.
If you find any, you can use them.
The #12052834 CPA is still Active (as a Green Color) and is supposed to be identical in dimensions/ fitment.


Delphi actually used to produced different Color Variants of most of their Connector Parts.
I would say that 85% of which have been discontinued... only keeping the Primary Color-Variant in production.

I actually have been try to hoard as much of that stuff as I can...
I offer some Custom Colored Connector Packages (a Mix and Match essentially).

 

Thanks, bud.

 

Sorry, the GT 280 Cable Seals that I normally use are:
-15366065 (Orange)
-15366066 (Yellow)
-15366067 (Tan)
-12191235 (Purple)

Also Cavity Plug:
-15305170 (White)

There are several others available, but these cover me for Cables between 18AWG through 12AWG (and some 10AWG).

 

I looked up those seal part numbers at Mouser and they claim,

* 12191235 (cable seal) and 15305170 (cavity plug) are 6.35 mm OD.
* All others are 5.75 mm OD.

Is this true? Of course, the AVID website has no drawings and almost no data on these parts. I can't even figure out the cable range for 15336674 and 15366061.

I remember the GT 150 story you explained to me with classic, mini, standard. Is this another case of that but in the GT 280 lineup?

 

No the GT 280 Parts do not have the same terrible Naming situation as the GT 150 Parts.

I believe that those dimensions may be an error... at some point I will double check.

But the difference in the Size is roughly a Radius of 0.012"

 

Thanks for posting this @vorteciroc . What is your preferred method of splicing from one to two wires when doing this job? The large wire is 10 gauge, which is a bit big for typical soldering if I remember right.

 

You are most welcome!


I recommend Splice Terminals.
QwkTrip actually Posted about a very popular Product-Line of Splice Terminals.
A user-friendly Selection-Chart has been included by QwkTrip.

Tyco Amplivar Splices (in the HyperLink below, Post #13):
TE Amplivar Splices

 

Wire CMA values are in the TE Connectivity document 82561. Assume 19 strand wire if you don't know specs for your wire.
https://www.te.com/commerce/Document...=SS&DocLang=EN

You can do 10 AWG into 2 * 14 AWG for 30A current rating. That will fit into some of the larger Amplivar splices.
I'm not sure the largest Amplivar splice will accommodate 2 * 12 AWG wires though, it's going to be tight.

The splices themselves are dirt cheap. I bought something like 20 of every p/n for $18. It was silly to even plan ahead when stuff is that cheap, just buy 'em all and figure it out later! The tool needed to crimp a bundle that large..... oh boy, not so much. You can probably buy a harness from Racetronix for less than the cost of tools and rework it a bit for your needs.

 

Here is a Crimper from Sargent, that Delphi used to produce for the Power-Pack Series:

Link

 

Thanks @vorteciroc and @QwkTrip . Those do look like the way to go. Anywhere you'd recommend buying some of these that doesn't break the bank? I invested in an inexpensive (relatively) Astro pneumatic crimper with interchangeable dies a while back. It's done well on the WeatherPack and MetriPack connectors so far. I'd love to find a die that fits it and these terminals - would it just use the "open barrel" die?. Still google searching over here for either.

Also thought that a non-insulated step-down butt connector could work. Like this one from Del City: Non-Insulated Step-Down Butt Connectors (delcity.net) . Figure the 223115 can go from a 10/12 to an 8. The 8 side should allow for 2 12 gage wires. This may prevent needing to buy a new crimper/die just for the TE pieces you referenced (barring finding a good inexpensive source and a die to fit my crimper).

Any helpful links or alternatives are welcome.

 

I usually direct people to Mouser.com...
But I have never really hunted around, to find who has the best Prices.