The Terminator EFI Input/Output Kit adds 5 extra input/output wires beyond what the base Terminator EFI harness provides — four input wires for Inputs 1-4 and one output wire for Output 2. These extra channels can be programmed for additional features and functions through Holley EFI laptop software.
Specifications:
- Product Type: Terminator Input/Output Wiring Harness
- Includes: 4 input wires (Inputs 1-4), 1 output wire (Output 2)
- Programming: Configured via Holley EFI laptop software
- Part Number: 558-420
Requires Holley EFI laptop software to program the added input/output functions.
FAQ
What does the 558-420 I/O kit add to a Terminator EFI harness?
It adds four extra input wires covering Inputs 1-4 and one extra output wire for Output 2 that aren't included on the base Terminator EFI harness.
How do I set up the added inputs and outputs?
These channels are programmed through Holley EFI laptop software, which also includes instructions for configuring them.
What part number is this kit?
This is Holley part number 558-420.

