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6.5L Diesel OPS Bypass/Fuel Pump Harness Upgrade

OPS Bypass/Fuel Pump Relay Harness For All 6.5L GM Diesels




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We do not currently ship outside of the USA


1992 - 2002 6.5L GM diesel

Part Number(s):



Tired of OPS failures and the related headaches? Our fuel pump relay harness upgrade addresses the shortcomings of the oil pressure switch/sensor and the factory fuel pump wiring by reducing the load across the OPS from 4 amps to 150 milliamps and carrying the actual fuel pump load through a high current relay. Furthermore, the system supplies power to the fuel pump through hefty 12 AWG wiring, as opposed to the factory 18 AWG setup. The result is vastly improved OPS reliability, extended fuel pump service life, and more consistent fuel pump performance. Additionally, some owners report significantly easier and quicker starts with less cranking.


Installation will take the average DIYer approximately 1 hour and requires only basic tools; all necessary hardware is included. This product comes with a 1 year warranty on the provided fuel pump relay and a 3 year warranty against material/manufacturing defects (both unlimited mileage).



• Reduces oil pressure switch electrical load from ~ 4 amps to ~ 150 milliamps (0.15 amps)

• Provides more consistent voltage to the fuel lift pump

• Prolongs oil pressure switch/sensor and fuel pump service life

• Powers fuel pump through robust 12 AWG wires (vs factory 18 AWG)

• High capacity 40 amp automotive relay

• Constructed using OEM connectors for a perfect, problem-free fit and finish

• 1 year relay warranty, 3 year harness warranty (unlimited mileage)

• Includes comprehensive, full color installation manual

• Made in the U.S.A. w/ primarily U.S. materials

Application Notes

1992 - 2000 Chevrolet Silverado 1500/2500/3500 (6.5L diesel)
1992 - 2002 Chevrolet C3500HD (6.5L diesel)
1994 - 1999 Chevrolet Suburban/Tahoe (6.5L diesel)
1992 - 2000 GMC Sierra 1500/2500/3500 (6.5L diesel)
1992 - 2002 GMC C3500HD (6.5L diesel)
1994 - 1999 GMC Yukon (6.5L diesel)

Additional Details



Part Number:





1 yr relay/3 yr harness, replacement only

Shipping Weight:

2 lbs

Estimated Delivery:

2 - 4 business days

Domestic shipping: This items ships for FREE to any address within the continental United States. Orders received by 2:00 pm PST are typically processed and shipped same day, Mon - Fri. Orders received after 2:00 pm PST or on weekends are shipped the following business day. Items are shipped to your confirmed PayPal address.

International shipping: We currently do not offer shipping outside of the United States and its territories.

Return Policy: Customer satisfaction is our highest priority. Unused, unopened products may be returned hassle free within 30 days. To initiate a return or for any additional customer service related questions, please contact us.