G7 Fuel Pump Wiring Harness HD - TB HD
Quick Overview
- Plug-and-play for 1984-87 Buick Regal Grand National, T-Type and GNX. No cutting or splicing.
- HD 630-series relay and fuse holder with 10 AWG copper power and ground. Runs single pumps up to 525 LPH.
- 6-0-X Weather Pack input plugs into the factory harness. Metri-Pack 280 output fits Racetronix FPS-G7 EQ hangers, or add FPAH-077 for Weather Pack hangers.
- Alternator-direct power. The fuse holder bolts to the alternator and the ground goes to the tank strap bolt, so no drilling.
- Add the BGK-001 body ground kit to replace the thin factory battery-to-body ground. Crimp-monitored, circuit tested, limited lifetime warranty.
Show More
$84.99
per EACH (USD)Turbo Buick HD Fuel Pump Wiring Harness
Plug-and-play hotwire harness for 1984–1987 Buick Regal 3.8L turbo cars
High-performance fuel pumps draw far more current than the factory pump circuit was built to carry. This harness takes the pump load off the factory wiring and feeds the pump directly from the alternator through a heavy-duty relay and fuse holder. Nothing is cut or spliced, and the factory configuration stays intact.
This HD harness has a 3-position Metri-Pack 280 (30 A) output connector. It plugs directly into current Racetronix FPS-G7 EQ-series hangers (shown in Related Products below), which have the HD intermediate harness built in.
It does not plug directly into the 3-position Weather Pack connector on a factory hanger, an older Racetronix hanger, or an aftermarket hanger. For those, add the FPAH-077 adapter listed in the Add Ons below.
The FPS-G7255EQ and FPS-G7255EQ2 hangers already include an FPAH-077 in the box.
Applications
| Vehicle | Years | Engine |
|---|---|---|
| Buick Regal Grand National | 1984–1987 | 3.8L turbo |
| Buick Regal T-Type | 1984–1987 | 3.8L turbo |
| Buick Regal Limited / Turbo T | 1986–1987 | 3.8L turbo |
| Buick Regal GNX | 1987 | 3.8L turbo |
This harness may also fit other G-body cars of the same era. Email [email protected] to confirm before you order.
Specifications
| Pump rating | Single in-tank pumps up to 525 LPH (Walbro F90000285) |
| Relay | Heavy-duty 630-series weatherproof relay |
| Fuse | 630-series weatherproof fuse holder, 25 A fuse |
| Power and ground wire | 10 AWG automotive-grade stranded copper |
| Input connector | 3-position Weather Pack, 6-0-X keying (plugs into the factory chassis harness) |
| Output connector | 3-position Metri-Pack 280 (30 A) |
| Power source | Alternator battery terminal |
| Ground point | Rear tank strap bolt, driver’s side |
| Loom | Nylon, GM spec GMP.PA6.003 (-40 °F to 300 °F) |
Harness Input Side: Weather-Pack Keying & Pinout
NOTE: This guide applies ONLY to the INPUT connector of the Racetronix Hotwire Harness.
3-POS 6-0-X
(Standard Harness)
| Cavity | Function | Wire Color |
|---|---|---|
| A | Ground | Black |
| B | Level Sensor | Violet |
| C | Relay Trigger | Gray |
Look at the mating face of the connector with the latch pointing up. Each cavity’s key is named by its clock position: 0 for 12 o’clock, 3 for 3 o’clock, 6 for 6 o’clock, 9 for 9 o’clock, and X for no key slot. Reading left to right, this harness is keyed 6-0-X to plug into the factory Turbo Buick chassis harness.
How it works
Power feed
Power comes straight off the back of the alternator, where charging voltage is highest. The fuse holder bolts into an unused hole on the back of the alternator with the supplied stainless bolt, so it stays out of sight and the unfused section of wire is only about 4 inches long. No self-tapping screws or extra holes are needed.
The 10 AWG main feed is several gauges heavier than factory wire, so voltage loss between the alternator and the pump is negligible.
Ground
The pump needs a good ground as much as it needs a good power feed. The harness ground is built into the main harness as one piece. A ground clip fastens to the edge of the tank, and all grounds, including the factory ground, run to a common piercing ring terminal on the driver’s side rear tank strap bolt. The relay mounts on the same bolt, so nothing has to be drilled.
The factory ground is never looped through the power connector. Every wire gets its own seal, so moisture stays out of both the hanger connector and the harness.
Body ground upgrade (recommended)
On most Turbo Buicks, the only ground between the battery and the body is a thin 10 AWG wire that runs from the negative battery terminal boot to the inner fender. Many owners assume the big cable from the battery to the engine block takes care of grounding. It doesn’t. That cable is the starter ground, and the engine sits on rubber motor mounts and rocks back and forth, so it is not a dependable path to the body.
The pump, the relay and everything else bolted to the body return through that thin factory wire. On cars this age it is often corroded, and a weak body ground costs pump voltage just as surely as weak power wiring does.
The BGK-001 body ground kit, listed in the Add Ons below, fixes this. It includes:
- An 8-inch 8 AWG multi-stranded copper ground cable with a heavy-duty 3/8" ring terminal on each end. One end bolts to the inner fender and the other to the negative battery terminal.
- Two plated brass side-post battery nuts with accessory taps, so the new ground and other accessories attach right at the battery.
No changes to the factory battery cables or boots are needed.
Voltage
Racetronix recommends an alternator voltage booster with all of its fuel pump systems, including factory pumps. Inline pump boosters such as the Kenne Bell Boost-A-Pump are not recommended.
What’s included
- HD fuel pump harness with 630-series relay and fuse holder
- 25 A fuse installed, plus a spare 25 A fuse
- Integrated tank ground clip and ring terminal
- Stainless steel mounting hardware
- Dielectric silicone grease for the ground clip and ring terminal
- 25 black wire ties
Frequently asked questions
I have a factory or aftermarket hanger with a Weather Pack connector. Can I still use this harness?
Yes. Add the FPAH-077 adapter. It plugs between the harness and the hanger’s 3-position Weather Pack connector.
I bought an FPS-G7255EQ or FPS-G7255EQ2 hanger. Do I need to order the FPAH-077?
No. Those hangers ship with an FPAH-077 in the box.
What’s the biggest pump this harness will run?
A single in-tank pump up to 525 LPH, such as the Walbro F90000285.
Do I have to drill any holes?
No. The fuse holder uses an existing hole in the back of the alternator, and the relay and ground share the rear tank strap bolt.
Does the factory fuel pump relay still do anything?
Yes. It now only switches the new heavy-duty relay. The pump current runs through the Racetronix harness instead.
Questions and support
Have a question before you buy? Email [email protected].
Racetronix provides technical support to verified customers through our support forum, not by phone or email. Please request forum access when you place your order so your account is approved before your parts arrive. The forum is moderated, open 24/7, and holds a knowledge base going back to 1999.
