Universal Quad Heavy-Duty Fuel Pump Wiring Harness

Quick Overview

Supports four independent fuel pumps at 30 amps each (max)
Fully Plug & Play with our quad fuel pump modules
Weatherproof OEM quality construction
4x relay ground control connectors for PCM or pressure switch control
IQPH intermediate interface harness required - vehicle platform dependant

Item #: UQPH-4P

$299.99

per EACH (USD)

In Stock & Ready to Ship

UQPH-4P Universal Quad Heavy-Duty Fuel Pump Wiring Harness

The UQPH-4P power harness is engineered to support up to four high-flow fuel pumps using entirely independent, heavy-duty circuits.

Key Specifications & Features

Dedicated Power: Features 10-gauge positive and negative wires for each of the four fuel pumps.
Independent Circuits: Each of the four circuits includes a dedicated:
- 40 Amp rated 630-Series Fuse Holder.
- 40 Amp rated Relay.
Pump Compatibility: Each circuit safely supports a 30 Amp continuous current draw, easily handling Walbro 450/525/535 pumps even under high-boost/high-pressure conditions.
Staging Control: Includes a dedicated Ground Control Connector for each relay, allowing for:
- PCM Control: Use a Powertrain Control Module (PCM) to control the ground side of each relay coil for precise, staged pump activation.
- Pressure Switch Control: Plug in a pressure switch to stage pumps based on varying boost levels.

Operational Details & Staging

Primary Pump Activation

The positive side of all four relay coils is combined. This allows them to be controlled by the primary fuel pump output on most factory and aftermarket PCMs (or a simple ignition positive source).

A ground control jumper (included) is used to enable one circuit as the primary pump. This pump turns on automatically with the ignition.
The other three circuits can then be controlled via a pressure switch or PCM for staging.

Important: To prevent fuel heating and excessive power draw, it is not recommended to run more than one pump during idle and light cruise conditions.

Required Interfacing Harness (IQPH)

The UQPH-4P harness features a 10-position interface connector designed for use with our IQPH-x Quad Intermediate Harnesses (listed under add-ons). An IQPH is required for use with this harness.

The IQPH intermediate harness provides the following breakout points:

10-position interface connector for the UQPH-4P.
6-position output connector for the fuel pump assembly/module/hanger.
Heavy-duty combined ground ring terminal for the fuel pump assembly/module/hanger.
Vehicle/platform-specific interface connector to pass through the level sensor signal and PCM pump trigger.

*For universal or custom applications, we offer universal breakout harnesses and connector sets for DIY requirements.

System Power Requirements

When running a quad-pump system, the combined current draw often exceeds the capacity of a factory alternator.

Current Draw: With four Walbro F90000285 (525) pumps running simultaneously, current draw can easily approach 100 Amps under high-boost conditions.
Voltage is Critical: Most fuel pumps are highly sensitive to voltage. It is imperative that Wide Open Throttle (WOT) voltage be maintained at 14.0 VDC or more to ensure rated flow capability. A 1.5–2.0 volt increase can result in a 20%+ gain in pump flow.
Recommendation: We strongly recommend a 240 Amp or higher Mechman Alternator for reliable, race-proven applications.

What's Included

4 x Relay ground control jumpers
4 x Relay ground control connector sets (for PCM interfacing)
4 x 30 amp ATC fuses (installed)
4 x 30 amp ATC fuses (spares)
4 x 25 amp ATC fuses (spares)
Assorted Nylon wire ties
Silicone Dielectric Compound
SS mounting screws

Frequently Asked Questions (FAQs)

Question	Answer
Can I use this for pumps other than Walbro?	Yes. It supports any fuel pump requiring 30 amps or less per circuit.
Does this support PWM (Pulse Width Modulation) control?	No. The relays are electro-mechanical. They would need to be replaced with electronic relays by the end user for PWM operation.
Can I use this for a 2 or 3 pump setup?	Yes, it can support fewer than four pumps, but a dedicated 2- or 3-pump harness from Racetronix may be more economical.
Can I mix and match pumps?	Yes. It is common to use a smaller primary pump for cruising (reduces heating/power draw) and high-flow pumps for the staged circuits (WOT). Each circuit must be properly fused for the pump being used (e.g., 25A for W450, 30A for W525/W535).
Does Racetronix offer custom modifications?	No. Our harnesses are mass-manufactured. We can sometimes make simple changes, but generally, customers use our accessory offerings to fulfill custom requirements. Please consult our sales team beforehand.
Are these harnesses repairable?	Yes. Racetronix offers a full line of components (connectors, relays, terminals, etc.) so customers can perform their own repairs.
What outputs does my PCM require in order to control the four pumps with this harness?	In most cases, factory and aftermarket PCMs have a positive (+) output for the primary fuel pump control. This positive (+) output must be connected to the gray wire in this harness which will provide positive (+) power to all four relay coils. (Our IQPH harnesses take care of this connection as a PnP solution). If you do not have a positive (+) PCM output, this wire can be connected to a positive (+) ignition source. The ground side of each relay coil is routed to a dedicated 2-position connector called the relay ground control loop. The second terminal on each one of these ground control loop connectors is wired to chassis ground/negative (-). When a supplied jumper is plugged into any one of these connectors, the ground circuit to the relay will be completed. Any relay with this jumper installed will activate with PCM or IGN +. This is generally used for the primary pump. The other three connectors are usually hooked up to one of our HPS pressure switches or preferably a PCM which can control three additional pumps which should be staged to come on sequentially as fuel demand increases.