Lots of notes and plan out what you are doing. Most these harness have poor documentation so far as overall wiring diagram. Before you install it, get a meter/ continuity tester and find out where every wire end goes
Wire up a circuit, and power it up and test for shorts. Get yourself a large wattage bulb, like a headlight or an 1157 turn/ tail bulb and socket, and wire it with pigtails, to the shell and the two bulb contacts. Parallel the two wire pigtails so you have ground and then both filaments in the other terminal.
When you power it up for test, put the large bulb in series with the battery ground. That way IF there is a short, all that will happen is that your test bulb will light.
Continue to test each circuit as you go so you don't get a bunch of problems stacked up
Be aware most these harnesses don't fully address "Mopars." One problem is usually the IGN1/ IGN2 connections at the key switch. Originally IGN2 was a brown, that went out into the engine bay and connected to the coil+ side of the ballast resistor. IF YOU are not using an ignition with a ballast, you need to jumper those two switch contacts together.
Don't be afraid to add relays. I would use two relays for headlights--one for high, one for low, powered by the dimmer switch. I would use another relay powered by IGN1 by the key to supply underhood loads, and power it off a good big (fused) lead from the battery, at least no12 or no 10.
