I would just power one at a time and look for the correct result if I was making it.
Powering one wire at a time and looking at all them will be ok. Just check the powered wire is HIGH and all others are LOW. Running through them all will take way less than a second I would think unless you want to add delays to see LEDs running.

 

Putting a different voltage on each wire requires NO LOGIC AT ALL. And then looking at each pin for a correct voltage could be done with a multiplexer. AND it would immediately detect bridges and opens and mis-wires. An added advantage would be not requiring much communication between ends of the harness.

 

Hello everyone,
I’d like to thank you all for your help in bringing my project to life,t’s almost complete now.
I'm still struggling with implementing the resistance test for my project.it's the only part I haven’t been able to figure out yet.

 

What sort of assembly error would lead to an excessive resistance in a harness connection???? OPens, crosses and accidental connections between wires are the types of failures normally tested for.