This is for a DC5 BTW, but anybody using a DC5 engine harness can use this method.
Step 1, get a resistor box.
I assume everyone knows to get a resistor box off of an older model honda, I got mine off of ebay for $15. Buy one that includes a pigtail of wires that plug into the connector on the rbox, that way you can splice in the pigtail without having the rbox permanantly mounted onto your engine haness. You only need a few inches of wire unless you need to mount it further away (I suggest you pick a mounting spot before you buy)
Step 2, wire it in.
The rbox needs to be installed between the +12v source and the injectors. The rbox itself has 5 wires, 1 common wire and 4 wires (1 for each injector) for the loads. Josh showed me how a connector (C104) is used for power distribution on the engine harness. C104 looks like a connector that itn't connected to anything, it's on the drivers side of the engine here:
![Image]()
Here is the pinout of C104:
![Image]()
Power comes into C104 then everything that needs power has it's own power wire coming out of C104.
The injectors get power from C104-19, C104-20, C104-21, and C104-22
Looking at the top of the connector there are a group of yellow/black wires, pin 24 is the far right wire, now the fun part, you have to cut all 4 injector wires, leave some room to resplice in case you screw up. I strongly suggest you use a meter to verify that the 4 wires connect to the 4 injectors (Since Honda does not specify an exact wiring order) One of the 4 wires coming OUT of C104 needs to be spliced to the common wire from the resistor box, then the 4 injector wires get spliced to the 4 load wires from the rbox, when you're done it should look something like this:
![Image]()
I used simple crimp connectors since my car does not get driven in the rain. You might want to solder the wires and cover them with heat shrink for greater durability.
Step 3, mount the resistor box.
I used an unused stud, mounted the box, plugged it into the engine harness. Worked forst time, here's my finished install:
![Image]()
Step 1, get a resistor box.
I assume everyone knows to get a resistor box off of an older model honda, I got mine off of ebay for $15. Buy one that includes a pigtail of wires that plug into the connector on the rbox, that way you can splice in the pigtail without having the rbox permanantly mounted onto your engine haness. You only need a few inches of wire unless you need to mount it further away (I suggest you pick a mounting spot before you buy)
Step 2, wire it in.
The rbox needs to be installed between the +12v source and the injectors. The rbox itself has 5 wires, 1 common wire and 4 wires (1 for each injector) for the loads. Josh showed me how a connector (C104) is used for power distribution on the engine harness. C104 looks like a connector that itn't connected to anything, it's on the drivers side of the engine here:
Here is the pinout of C104:
Power comes into C104 then everything that needs power has it's own power wire coming out of C104.
The injectors get power from C104-19, C104-20, C104-21, and C104-22
Looking at the top of the connector there are a group of yellow/black wires, pin 24 is the far right wire, now the fun part, you have to cut all 4 injector wires, leave some room to resplice in case you screw up. I strongly suggest you use a meter to verify that the 4 wires connect to the 4 injectors (Since Honda does not specify an exact wiring order) One of the 4 wires coming OUT of C104 needs to be spliced to the common wire from the resistor box, then the 4 injector wires get spliced to the 4 load wires from the rbox, when you're done it should look something like this:
I used simple crimp connectors since my car does not get driven in the rain. You might want to solder the wires and cover them with heat shrink for greater durability.
Step 3, mount the resistor box.
I used an unused stud, mounted the box, plugged it into the engine harness. Worked forst time, here's my finished install:
