Crabtree10

I’m looking at doing a new wiring harness for my 78 D150. Any tips or suggestions? It has AC and cruise. I’d also like to change instrument gauges while I’m at it.

Kuvasz101

From memory. The wire harnesses came in 3 sections. Under the hood and headlights, under the dash wires and then harness to the rear lights etc. A tip when replacing the harnesses was with the wires still on the vehicle disconnect one at a time and replace with new. Another easy way to do without dealing with 2 harnesses is cut the existing wire leaving a 2-3 inch lead hanging so you can match up the new harness by color code. I found that helpful under the dash.

Iowan

I don’t know of any Dodge D150 specific wiring hardnesses available. One of the biggest problems with the original wiring is the connector at the firewall so going three inches in both directions from it probably won’t help. You could try to restore the connector and all the pins then possibly build a harness from there.

Kuvasz101

I'm unsure what you mean as far as both ends. I'm not saying cut the new wire harness ends, just cut the existing wire harness ends so you could match the new to it. I was assuming the wire harnesses were available but that is going back some years so you may have to build your own. We changed out the plugin box at the firewall and ran the wires across the engine and firewall just matching the existing-colored wires. For example......snipped the wires at the coil and alternator leaving a few inches and matching them up. The hardest rewires were from engine fires. You needed a similar car/truck to use as a wire diagram.

Tau511

Ron Francis sell an easy to use kit that is also super easy to modify if you don't care about being original.