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Thank you for visiting. We have opened up orders for the E-Series and G-series kits. Ford Kits Ship week of 10/18 and G-series kits ship First week of November!
Thank you for visiting. We have opened up orders for the E-Series and G-series kits. Ford Kits Ship week of 10/18 and G-series kits ship First week of November!

Wiring Harness for Differential and Tranfer Case 4x4 GM Van Conversion


The IFS 9.25 GM front differential utilizes an electronic actuator to engage the front CV axles and lock hubs in. It's nice to not have to get out of the vehicle to lock the hubs but there's some wiring involved to make this work with a manual shift transfer case. 

We utilize a New Process 261 transfer case in our builds, sourced from a 2001-2007 (early) Silverado 2500/3500 series. We've found it to be the most reliable and simple solution for our conversions. 

This Transfer Case + Differential wiring harness includes all the necessary wiring, looming, connections and sensors required to setup the 261 and the 9.25 for easy and reliable operation.

In a nutshell, the system uses a ground signal from the transfer case 4x4 activation to engage the front differential hub lock, which in turn activates the LED 4x4 indicator lamp inside the vehicle (all included). 

Each wire is labeled to where it needs to be run. For reliable operation, we've included a new sensor for the 261 and a new hub lock actuator for the front differential. We bench test each harness before final packaging to ensure it is working properly. You will be provided with a supplemental wiring diagram and support. 

***Harness available without lockout motor and/or different sensor, for specialty orders call before ordering. There are multiple wiring configurations for the 9.25 motor, hence our typical inclusion. 

Is it expensive? Yes, this harness is built by hand one at a time by Christy or Hugo at our shop. These are not built in a factory in China (if you'd like to buy 300 of them, we'll gladly find a way to make them more affordable!) 

Fitment Designed for: 

Van Side - 2003-2021 Chevrolet Express 2500/3500/4500 series vans. 

Truck Side - 1999.5-2010 Chevrolet Silverado / GMC Sierra 2500 + 3500 series 9.25 Front Differential and NP/NV 261 Manual shift transfer case (2001-early 2007)

Tools Required:

Standard hand tools. Wire strippers, crimpers, soldering iron and/or heat gun if desired. 


NP261 transfer case range sensor, waterproof connector, color-coded wiring harness with looming to lockout motor, fuse block, and in-cab LED light. Includes indicator light, fuse jumper, Dorman Hub Lockout motor (AC Delco/OEM available for additional - Call, wiring diagram and labeled cabling. 

Construction Notes:

14 gauge wiring, plastic looming, AC Delco motor pigtail, Dorman or GM/ACdelco products,

Tips / Skill Level:

1-10 (10 being most difficult) Level 4 - Basic wiring principles required. 

This product may work with other model vehicles.

Shipping, Fulfillment, Taxes, Quality, and Returns
  • Shipping: Our components are carefully wrapped and packaged and ship UPS, USPS, or FedEx, depending on what is available. If you require a particular carrier, please contact us ahead of your purchase.  Customers in Colorado may arrange for in-person pickup within 1-2 business days of purchase. 
  • Shipping/Fulfillment time for components: We typically ship within 1-2 business days of your order and we carefully monitor our inventory. In the event that we are unable to meet that timeframe, we will contact you and arrange either a full refund or a timeframe for fulfillment agreeable to the customer. 
  • Taxes: Colorado residents must pay sales tax of 7.5%, no sales tax is collected on out-of-state shipments currently. 
  • Quality and Returns: We are consistently complimented on the quality of our products and the ease of install. Components are hand-built here almost exclusively in Colorado by seasoned professionals who are fanatics about design and execution. If you are in any way disappointed in the components we will issue a full refund less the cost of shipping when the product is returned. If you decide to return any components that didn't apply to your build or you changed your mind about, shipping and a 15% restocking fee will be deducted from the purchase refund.