I’m facing an interesting dilemma. I have a 20 conductor cable (that I built) going into the cabin on my STI, intended to connect to the DAQ system. It goes to the engine bay and terminates in a 20 pin Deutsch HDP connector. From that I need to run to 18 different sensors, where each sensor has a sensor output, plus power and ground.

Option 1: I could do it like an OEM factory harness would work.. I would have one or two power and ground wires going around the engine as well as the signal wires, and at locations close to the sensors the signal wire would connect, and the power and ground would have a tap. This would be your typical black tape wrapped around plastic split loom tubing. The plus side is the ease of building, but once it is done and all wrapped up, it takes some work to add more sensors, or change the location of a sensor. It also means a bunch of splices in the 5v and ground wire. Another minor issue is that I need to add some 5V pullups for some of the sensor, so that would have to but put in the harness as well.

Option 2: I could make a custom PCB like I did for my GTR. (See picture 2 and 3). In that case the PCB had the pullups, plus the +5 and Ground aggregation. I used PCB mount screw terminals, then I then connected to HDP connectors. This solved the multiple things needing connection to a single 5V and GND wire. I could even skip the HDP connectors on the sensor side, and have each sensor wire connect right into the terminal blocks. In this way every sensor connects back to one place.

Option 3: I could make a new PCB and case, but using something like the EN3(or M8, or Micro-Con-X) connector in picture 4. That is similar to how the AIM Dash sensors are connected. For 18 sensors I would need 18 of these, which would be a difficult fit in a single panel. I’d probably need 2 or 3 panels with these connectors on them, all aggregating down to the 20 pins HDP connector. The advantage of this setup is each sensor cable is just a plug-and-play fitting that can be moved, replaced, etc.

Any thoughts?