LS2_PKG O2_Detail FuseBox_Close 53_Caddy_eng5.jpg 53_Caddy_eng4.jpg


Harness images shown are sample images. Actual product may vary.

Our stock harnesses are 4 feet from the rear of engine passenger side.

Available options Transmission, Electric Fans, Air conditioning and Upgraded Braided loom.

Please call for custom ECM and/or Fuse Box Location,  extra Length.

Please call for harness package with programmed computer and pedal $1095
add 6L80e/6L90e transmission wiring for additional $75

add transmission controller (4L60e/4L65e/4L70e/4L80e) for $200 more.

**Harness orders usually ship with in 15 to 20 business days after  ordering**

Built From Scratch Stand Alone Engine Harness

An engine management harness is pretty much what you will find from most wiring harness companies. Basically, it contains all of the necessary functions to make the engine start and run, while also supplying any necessary signals from the computer such as speedometer and tachometer.

Our engine management harness contains any fuses and relays that will be needed, and the required splicing on the consumer’s end of it is fairly basic. There are no main power feeds required for this harness, just a single switched ignition power will switch a relay in the harness that in turn, supplies 12V power to all of the required engine sensors and the ECU.

These harnesses are designed for the hot rod, or project car that will be using aftermarket or mechanical gauges. There is no output wire for oil pressure or temperature gauges since the aftermarket usually supplies sending units and wiring for these. The harness will have provisions to plug in to the stock oil pressure and coolant temperature sensors on the engine for use with OBD scanners/gauges.

All of our harnesses, whether it is a complete custom harness, or our engine management harness, come with an easily accessible DLC (Data Link Connector) that is usually long enough to be mounted in the passenger compartment. This allows for easy access to the ECU via a laptop or standard scan tool.
Harnesses come covered in standard OE split loom. Optional braided loom available for an extra charge.

The Fuses and Relays for custom harnesses can come one of 2 ways. Either the standard separation of all relays where they are mounted in the engine compartment usually on the firewall or fender, or a compact OEM looking Fuse/Relay center where all of the components are in one central location. The fuse/relay center style is shown below. All of the fuses and relays are labeled on the underside of the covers just like a factory vehicle.

covers fuse_relay

Not sure if you have VVT or DOD/AFM features?
2007 and up 58x engines have the option of Variable Valve timing to alter the camshaft timing while the engine is running. You can look for a few things to indicate if you have VVT. First, the plug on the front of the engine pointing downward on the driver’s side will have 5 wires going to it. A non-VVT engine will have 3 wires.

Front timing cover with 5 wire connector for VVT.     VVT Bulge in Timing cover
Front timing cover with 5 wire connector for VVT, and bulge in the timing cover under the water pump are indications that the engine you are working with has VVT.

Engines with AFM/DOD have a 5 pin connector next to the oil pressure sensor in the valley cover under the intake. This should be noticeable from the back of the engine. Also, raised vanes should be visible on the valley cover instead of it just being flat and smooth as on non-DOD/AFM engines.

View from back of engine showing DOD/AFM connector.
View from back of engine showing DOD/AFM connector.


This Harness Fits V8 Engines out of these vehicles ( 4.8, 5.3, 6.0, 6.2, 7.0 )

CARS LS2, LS3, L76, L77, L98, L99,

TRUCKS/ SUV/ VANS Ly2, L20, LMF, LH6, LH8, LH9, LY5, LMG, LC9, L92, L94

Additional information

Weight 15 lbs
Dimensions 12 × 12 × 8 in
Computer Type


Transmission Type

None, 4L60E / 4L65E / 4L70E, 4L80E / 4L85E, T56 / TR-6060, 6L80E / 6L90E

Add 2 Fans

No, Yes

Air conditioning

No, Yes

Braided Loom

No, Yes

Vehicle Engine come from

Truck/SUV, Crate


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