Bare Wire - Wiring with no covering that will be structurally taped to hold its form. Best if you plan to cover yourself or are running a lightweight build. This option will be used across the entire harness unless otherwise specified.
Plastic Convoluted - Standard covering which is commonly found on OEM wiring. Moderate protection for wiring. This option will be used across the entire harness unless otherwise specified.
Harness Tape - A cloth covering for protection against heat, chemical, and abrasion of your wire harness. Lightweight and easy to form for installation. High protection for wiring. Can combined with braided loom for the ultimate in protection and appearance. This option will be used across the entire harness unless otherwise specified.
Braided Loom - This will provide low to moderate abrasion protection. It is best used for low concern builds due to having many small holes. It is very lightweight and flexible and looks great. Can be combined with harness tape for the ultimate in protection and appearance. This option will be used across the entire harness unless otherwise specified.
Nomex Braid - Nomex is a flexible fire retardant fabric which is commonly used in military/aerospace applications where lightweight but resilient wiring protection is desired. This will loosely wrap around the harness and will provide heat and flame resistant protection that will not wear or degrade due to its construction properties. This option will be used across the entire harness unless otherwise specified.
High Temp / Fire Retardant Coverings - Recommended for extreme or race applications subject to high heat, this fiberglass covering will be used in the lower portions of the harness which run near the exhaust manifolds. The reflective fire retardant covering which is resistant to direct high heat will ensure the wiring underneath does not become melted, brittle, or damaged. This would be combined with any of the above coverings as it will only cover a few key areas. If you would like to have the entire harness covered in fire retardant material, please contact for a quotation.
Standard Power Distribution Center - Standard option consisting of a series of 4 position fuse holders and 4 relay modules for providing power to the harness required for operation. This will not replace any vehicle fuse/relay modules which control lighting, air conditioning, or other vehicle functions. This unit is fairly large, and is unsealed from the front and back of the unit. The fuse holders do have 2 mounting holes each.
Sealed Power Distribution Center - This performs the same tasks as the standard option, but has a smaller footprint allowing easier placement, and comes sealed to an IP66 rating through the use of terminal seals on the rear of the unit, and a sealed front cover. This will not replace any vehicle fuse/relay modules which control lighting, air conditioning, or other vehicle functions.
All LS Harness Connection engine harnesses will come with an instruction manual available for download to the customer. Depending on the build selected, there may be a handful of loose wires to integrate the harness to the vehicle. These wires are detailed in the installation manual, but due to repetition of GM color codes, there may be some wiring with matching colors. For ease of installation, you may choose to have your wiring harness labeled which will include all connection points and loose wires.
Standard harness builds will pass through the factory firewall and seal utilizing a sliding rubber grommet. For many applications this is fine and will not have any issues for the lifetime of the harness. LS Harness Connection does offer bulkhead connections which are weathertight passthrough options that disconnect at the firewall. These provide a few benefits over the sliding grommet like a IP67 seal to ensure no dirt or liquid penetration into your wiring or cabin from the engine bay and ease of installation and removal of the powertrain with the harness installed onto the engine. This is achieved because instead of the wire passing through the firewall, there is a break which can be disconnected at the firewall which allows all connections on the engine to be maintained.
If you wish to run a content sensor for use with E85 compatible computers and injectors, you may choose to have the sensor wire added into your engine harness. This will also require a content sensor, a compatible ECM/PCM with the ability to read ethanol content, and tuning to use the sensor values.