Engine Computer (ECU) and/or programming sold separately

*1998 trucks and all 99-2000 V6 trucks will require purchase of additional C101 Body connector adapter:
98-2000 S10 C101 Adapter

The above options provide selections from our current stock inventory of harnesses for the S10 LSx swap. Our inventory harness configuration leaves the ECM in the stock location on the overflow tank under the hood.
Custom orders can be built if your installation does not fall under the above selections.

All S/T Truck LS swap harnesses include wiring for A/C, Starter, factory gauges, and ABS. All factory functions of the truck can be retained with this product. Wiring and relays for electric fans are also included.

The “truck intake” variation of these harnesses are configured with standard Multec 2 style injector connections. If you have Flex Fuel injectors, or any other variation, you will either need a harness made for your application, or purchase adapters for the different injectors. LS1 style intakes will have EV1 style connections.
All harnesses are configured with 5 wire MAF connectors intended to work with MAF p/n AF10043 or equivalent.
All harnesses are configured with flat 4 pin truck style oxygen sensors intended to work with Bosch p/n 13026 or equivalent.

These harnesses are meant for race/off-road applications, they do not contain any wiring for rear O2 sensors or EVAP canister purge systems. On-road emissions compliant harnesses can be made upon request.

Direct-Fit LSx/LT/Vortec for 1982-2004  Chevy S-10/ Blazer,  GMC Sonoma / S-15/ Jimmy

Our Direct-Fit custom wiring harnesses are plug-and-play, custom built, and designed specifically for your project utilizing a 97-up LSx or Vortec small block V8 engine. Each harness is built from scratch specifically for the application listed. In most cases a Direct-Fit harness will allow you to retain all of the factory vehicle functions and gauges after the engine swap.

The main difference between our Direct-Fit harnesses and a standalone engine management harness is that a standalone engine management harness is designed to do nothing except run the engine, and supply any necessary outputs such as speedometer and tachometer. Our Direct-Fit harness is built to include all of the functions that your vehicle will use, such as original gauges, any connectors that go to or through the firewall, relays to control the fans via the computer, and we will utilize the factory Neutral Safety switch when possible.

A Direct-Fit custom harness from Current Performance Wiring contains all of the electrical connections that are required for the vehicle that you are installing the new engine into. These harnesses include all necessary body connections to directly replace your original 4.3L or 2.2L engine harness and properly operate the new engine and transmission as if it all came directly from GM that way.

This harness is not only designed to plug right in to the project vehicle and engine, but since they are completely built from scratch, they can be made to your specs. If you are going for a clean install and want the ECU inside the passenger compartment, or all the way back in the trunk, we can make it exactly how you need, or if you are happy with things just how they were, we have inventory harnesses that will set the ECU back in it’s stock location on the overflow tank and take care of all your needs.

Direct-Fit Custom Harnesses come covered in standard OE split loom but optional Braided loom is available for an extra charge.

1998 and newer…
Things YOU will need to know…

First and foremost… we only build wiring harnesses for 94-up LT, LS, and Vortec engines. We DO NOT do wiring for TPI or Carburated engines in to any of these trucks.

In 1998 GM redesigned the interior of the S trucks, and made a new grille. To most people, this is pretty much the extent of what they know. On our end of the world, the Electrical system of the 98 and up trucks is VASTLY different from prior years. One main difference you will notice is the Underhood Bussed Electrical Center (UBEC) located in front of the ABS module on the Driver’s side fender. This box contains most of the relays and fuses for the engine components. This makes wiring in a new engine a bit easier because at least most of the power feeds and relay controls go to one central location.

If you are installing any of the LSx or Gen III Vortec engines (4.8, 5.3, 6.0, or 6.2L) We have developed a program that will allow just the LSx computer to be used in a 98 and up S-truck. This single computer will control the engine, allow the gauges (including tachometer) and ABS to work properly, control the electric fans, and control all other functions of the truck just like factory.

There will be 2 extra relays to be mounted on the firewall next to the existing 1 that is there now to control the electric fans.

LSx & Gen III Vortec harnesses start at $850

LS2/LS3/LS7/LS9 & Gen IV Vortec harnesses start at $850

*Ask about our sensor package including MAF and O2 sensors for a complete matched system.

Additional information

Weight 10 lbs
Dimensions 12 x 12 x 10 in
Year of S/T Truck

1998, 1999, 2000, 2001-up

Original Engine

2.2L 4 Cyl., 4.3L V6

Original Transmission

Manual, Automatic

2WD or 4WD

2WD, 4WD

Intake/injector style

Vortec Truck Cable throttle, LS1 Car Cable throttle, Vortec Truck Electronic Throttle

New Transmission

4L60E, 4L80E, T56, TH400, TH350, 5 Spd Manual

Auto Trans PRNDL Switch

Single Connector (03-up), 2 Connector (02-earlier), N/A

Front Accessory drive

Vortec Truck, Corvette

Need connections for CPW Fans

Yes, using the CPW Fan/Radiator kit, No, using my own fans

Loom style

Standard Corrugated Loom, Braided Plastic Loom