Michigan Motorsports Ignition Coil Harness Connector — Direct-Fit for GM LQ9–LSX 4.8–7.0L, OE Pinout

Michigan Motorsports replacement ignition coil harness connector restores reliable electrical connection for GM truck and LS-series coil packs.

If your factory coil harness has become brittle, cracked, or intermittent from heat and age, this direct-fit Michigan Motorsports harness is built to match OE wiring and pinouts for a wide range of GM 4.8L–7.0L engines. Sold as individual harnesses — select quantity 2 for a full eight-coil set — it replaces part number 89017477 and supports common truck and LS coil designs so you can fix misfires or wiring failures without rewiring or splicing.

Which engines and coil types will this harness fit?

This harness is designed for many GM V8 and V6 coil packs used in Chevy, GMC, and Cadillac applications. It covers LQ9, LQ4, LS2, LS3, LS7, LSX and common truck coils spanning 4.8L, 5.3L, 6.0L, 6.2L, and 7.0L engines. Note it does not fit D580 LS1 coils.

• Direct replacement for GM part 89017477.
• Compatible with D581 (12558693), D585 (10457730 / 19005218), D513A (12570616), D514A (12573190), D510C (12570616).
• Designed for the same pin layout and connector body as OEM harnesses for easy plug-and-play installation.

How do I install it correctly to avoid misfires?

Installation is straightforward when you match connectors by wire color and cylinder firing order. Each harness connector has a colored second wire — follow the color mapping to ensure each coil goes to the correct cylinder and retain the OEM routing to prevent heat damage.

• Purple wire → coil firing cylinder 1 or 8.
• Red wire → coil firing cylinder 2 or 7.
• Blue wire → coil firing cylinder 3 or 6.
• Green wire → coil firing cylinder 4 or 5.

What are the main benefits compared with keeping the old harness?

Replacing a degraded harness restores consistent coil voltage and reduces intermittent misfires caused by cracked insulation or corroded terminals. A fresh harness improves reliability under heat and vibration without needing coil pack replacements, saving time and money compared with diagnostic guesswork.

• Restores secure electrical connection to coil packs and eliminates brittle wiring failures.
• Prevents recurring misfires by delivering stable signals and power to coils.
• Saves installation time—OEM-form connector and correct pinout mean no cutting or rewiring.

Will this harness work with aftermarket or MSD coils?

Yes — the harness supports several common OE coil designs and is compatible with many aftermarket coils that accept the same connector styles. Verify connector style against your coil model before purchase; this harness matches the listed GM coil part numbers and most plug-in aftermarket equivalents.

• Compatible with MSD 8287-style and OE-equivalent plug designs when pinouts match.
• Confirm physical connector shape and terminal count with your coils prior to installation.
• Does not fit unique LS1 D580 coil connectors.

Who is this for: This Michigan Motorsports ignition coil harness connector is aimed at owners and technicians working on Chevy, GMC, or Cadillac trucks and LS-series engines who need a reliable, direct replacement for aging or damaged coil wiring. It’s ideal for DIY mechanics restoring ignition reliability, service shops eliminating intermittent misfires quickly, or anyone swapping coil packs who wants correct OEM-style connectors without cutting into factory wiring.