Overview Reviews Product Description 558-414 Holley EFI Terminator Main Harness Replacement main wiring harness for Terminator EFI kits 550-405 and 550-406. Product Videos Custom Field Product Reviews Write a Review Write a Review × 558-414 Holley EFI Terminator Main Harness Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *