wiring harness diagram for 1977 dodge d100 | eBay Find great deals on eBay for wiring harness diagram for 1977 dodge d100. Shop with confidence. Mopar Truck Parts :: Dodge Truck Technical Information 1961-1966 Dodge trucks had a fairly simple wiring harness that was point to point without a bulkhead connector. 1967 This was the first year since 1961 the wiring harnesses changed. 1968 1968 truck wiring harnesses were different from both earlier and later years (one year only). 1969-1971 In 1969, a firewall bulkhead connector was introduced.