I know I said I was going to work on the engine. But my mood changed. I've been playing with wires. First, I worked on the engine compartment wiring harness (minus the actual engine harness). I attempted to strip out everything I don't want - ABS, crash sensor, DRL stuff, about 1/2 of the lighting wiring, heater blower wiring, AC wiring and a few other miscellaneous bits. Next, I pulled what I think I want and need from the dash wiring harness. I got all that 90% complete. The remainder must wait until installation. I left all the extra wires coiled up near the firewall connectors until I'm sure I don't need them.
What I will finally have, in the end, is a combination of the original Ranger harness and what currently remains from the Explorer harness. Several reasons for this.
First, as mentioned previously, the Explorer is wired to OBDII architecture and the 93 Ranger is EECIV. They are vastly different. Most of the differences are in the engine bay, but many things spill inside.
Second,, I want the newer engine bay fuse/relay box. It has room for more circuits and relays. Pkus, some of those are required for the newer wiring design.
Third, I am keeping an auxilliary relay box in the engine bay. This will be repurposed for the common "headlight relay mod" where we use the switch circuit to control relays for the headlights. This keeps the high current power for the bulbs on shorter wiring and reduces voltage drop from the older circuit. Hence, slightly brighter headlights. The other relays in that box can then be used for auxilliary items like my light bar. I currently have several single relays and fuse holders scattered under the hood. Cleanup time.
There may be a fourth advantage. My electronic dash package from Holley will require roughly 28 wires to pass through the firewall. I may splice these into the "extra" pins on the Explorer & Ranger firewall connectors. I'm not 100% sure about that yet. Keeping them separate would make it easier to troubleshoot the Holley wiring if needed.
So, "do I know what I'm doing?" Only about 85%. But SOMETHING is going to happen. The mechanical is definitely the easier portion of this swap and quicker to execute.
Maybe.
The results of this effort, laid out roughly as it will go into the truck. View from the firewall. Clockwise from bottom right - connector that goes to engine harness, then the 3 firewall connector assemblies, OBDII port below, fuse/relay box, starter relay, auxilliary relay box, then the harnees across the radiator support to serve the cruise servo amplifier and windshield washer pump/tank. Alternator harness across the center with wires going to oil sump level/temp sensor.
Fuse/relay box with extra wires available.
One of the 3 firewall connectors showing the interior side wires
Same connector showing possible spare wires on engine side.
