Cat 40 Pin ECM to Cat 70 Pin Truck Adapter Harness (built to order)

Harness Adapter Application

This adapter is designed to connect the factory truck/vehicle harness from any 70-pin Caterpillar engine to a compatible 40-pin Caterpillar ECM/engine, making engine conversions straightforward while retaining the original chassis wiring.

Compatible 70-Pin Engine Prefixes

• 3406E – 2WS
• 3406E – 1MM
• C15 – 6NZ
• C15 – MBN
• C-15 ACERT – BXS
• C-15 ACERT – MXS
• C-15 ACERT – NXS
• C16 – 7CZ
• C-13 ACERT – KCB
• C12 – 2KS
• C10 – 3CS
• C10 – MBJ

Compatible 40-Pin Engine Prefixes

• 3406E – 5EK
• 3406E – 1LW
• 3406E – 6TS
• 3406E – 5DS
• 3176B – 9CK
• C12 – 1YN
• C12 – 9NS
• C10 – 2PN
• C10 – 8YS

Application:
Connects the truck/vehicle harness from any 70-pin CAT engine prefix listed above to any compatible 40-pin CAT ECM/engine prefix listed above. Ideal for engine swaps and conversions without modifying the factory chassis harness.

Important Note:
If your truck is equipped with the factory J1939-powered instrument cluster (generally found on 2006 and newer trucks), this adapter may not be compatible. If you’re unsure whether it will work with your engine and chassis combination, feel free to contact us before ordering.