I thought I was about to be in $450 for a new part for my car, turned out to be a $1 fuse.
Ground wire in this picture would be seen to the left of the DME, the multiple wires bolted to the trunk wall at the top left of the DME. It's only one bolt, not the bundle of harnesses to the lower left pictured. That's how most of the engine harnesses that I've seen on these cars work, at least.