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SKU: FPE-HAR-GM-NSBU-0405 | UPC: 732777409600
Fleece Performance 04.5-05 GM 2500/3500 Duramax (w/Allison Transmission) NSBU Pigtail
The Fleece Performance NSBU Pigtail replaces the factory wiring harness on 2004.5-2005 Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks equipped with 6.6L LLY Duramax diesel and Allison 1000 transmission. Corrosion at the firewall NSBU connector leads to no-crank no-start issues and transmission limp mode which this direct-fit pigtail resolves. Built with TXL cross-linked polyethylene wire and sealed Weatherpack connectors it ensures dependable signal delivery and resistance to moisture road salt and harsh conditions.
Key Features
- Plug-and-Play Installation: Matches OEM firewall connector locations for fast replacement without cutting or splicing wires.
- Corrosion Protection: TXL 18-gauge wire with high-temperature rating and weather-tight silicone seals blocks water dirt and chemicals.
- NSBU Switch Reliability: Restores neutral safety and backup switch signals to prevent starting failures and limp mode activation.
- Exact OEM Fit: Precision-engineered for 04.5-05 LLY Duramax (VIN 8th digit Y) with full Allison transmission compatibility.
- USA Made Quality: Assembled by Fleece Performance using precision-crimped terminals for consistent electrical contact and durability.
Product Notes
- Confirm your truck has Allison automatic transmission and LLY Duramax engine (VIN 8th digit Y).
- Inspect firewall connector for damage before install to ensure full repair.
- Special order item processing may take 1-2 extra days if not in stock.
Installation Notes
- Professional installation recommended.
- Disconnect negative battery cable and relieve fuel pressure before starting.
- Access pigtail at driver-side firewall transmission harness connector no special tools required.
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2004-2005 | Chevrolet | Silverado 2500 HD | Base |
| 2004-2005 | Chevrolet | Silverado 2500 HD | LS |
| 2004-2005 | Chevrolet | Silverado 2500 HD | LT |
| 2004-2005 | Chevrolet | Silverado 2500 HD | WT |
| 2004-2005 | Chevrolet | Silverado 3500 | Base |
| 2004-2005 | Chevrolet | Silverado 3500 | LS |
| 2004-2005 | Chevrolet | Silverado 3500 | LT |
| 2004 | Chevrolet | Silverado 3500 | WT |
| 2004-2005 | GMC | Sierra 2500 HD | Base |
| 2004-2005 | GMC | Sierra 2500 HD | SLE |
| 2004-2005 | GMC | Sierra 2500 HD | SLT |
| 2004-2005 | GMC | Sierra 2500 HD | WT |
| 2004-2005 | GMC | Sierra 3500 | Base |
| 2004-2005 | GMC | Sierra 3500 | SLE |
| 2004-2005 | GMC | Sierra 3500 | SLT |
| 2004-2005 | GMC | Sierra 3500 | WT |
Why Choose Fleece Performance?
- 20+ years specializing in Duramax diesel components and tuning solutions.
- High-grade materials tested for heavy-duty truck environments.
- Engineered and assembled in the USA for precise fit and durability.
Frequently Asked Questions
-
Q: Does this fit early 2004 Duramax trucks?
A: Fits 2004.5-2005 models with LLY engine (VIN 8th digit Y) and Allison transmission check VIN for exact match. -
Q: What wire and connector materials are used?
A: TXL 18-gauge wire rated for high temperatures with OEM-style Delphi Weatherpack connectors and silicone seals. -
Q: What is the warranty and install time?
A: Limited lifetime warranty against defects installs in 15-30 minutes with basic hand tools.
Shipping & Handling
- Method: UPS Ground / USPS Priority
- Availability: In stock - ships same or next business day
- Packaging: Protective padded envelope 6 x 4 x 1 inches
- Weight: 0.1 lbs
Fleece Performance
Fleece Performance Engineering has grown from a small Indiana operation into one of the most respected names in high-performance diesel upgrades, with a product catalog built specifically around the Duramax and Cummins common rail diesel platforms that dominate the high-horsepower diesel community. Founded by brothers Brayden and Chase Fleece in a rural west-central Indiana pole barn, the company established itself as a technology leader in common rail injection systems within five years, developing the Cheetah turbocharger line and the TurboBrake electronic exhaust brake that have become standard references for what diesel performance engineering can achieve. Fleece operates from an 18,750-square-foot Brownsburg, Indiana facility capable of in-house design, manufacturing, assembly, and testing, placing them among the high-output diesel specialists who supply race teams and serious street performance builds. This collection covers Fleece Performance's full range of Duramax and Cummi...
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