2017 Parasitic Draw

[JustATech6996]

Hello all, i have a bad draw that will kill the battery overnight. I narrowed it down to the fuse block but the wiring side of it that is non repairable unless I buy a whole new harness. I unplugged PCM relay (big grey one) and the black one directly next to it. That seemed to keep the battery from draining overnight and she started right up. Anyone have the same issue? Maybe a PCM or just a bad relay. Or even worse high resistance in a wiring mess. Let me know what you all think, new to these fords.

 

[Steve8316]

There's no reason to replace the wiring harness, and high resistance would be the opposite of a draw. If the PCM is staying awake & draining the battery, that's not parasitic - it's some problem on the vehicle causing the PCM to stay awake. A similar symptom appeared on mine when I swapped from column shift to floor, before I got the floor shifter fully wired. It seems that the In-Park switch was keeping either the PCM, BCM, or ICM awake. Once I finished the wiring, the draw went away. So you need to consider what happened just before your symptom appeared.