This Holley plug-and-play alternator harness is built for late-model engines running Pulse Width Modulated (PWM) alternators, covering most 2007+ GM engines and most 2005+ Ford engines.
Specifications:
- Application: 2007+ PWM GM alternators (also fits most 2005+ Ford engines)
- Compatibility: Plug-and-play with Holley EFI and Terminator X main harnesses
- Use: Late-model OEM alternators
- Includes: Detailed installation and software configuration instructions
- Part Number: 558-475
FAQ
What alternators does this harness fit?
Most 2007+ GM engines and most 2005+ Ford engines equipped with Pulse Width Modulated (PWM) alternators.
Is this a plug-and-play harness?
Yes — it plugs directly into Holley EFI and Terminator X main harnesses.
Does it come with installation instructions?
Yes — detailed instructions for installation and software configuration are included.

