Cruise control stoped working after engine harness changed.

[Waterloo]

First, check the fuse and any relays if there is one or more, I do not know. What truck is this? That will help too.

Also, this may sound silly, but is the harness wired for cruise control? My buddy just replaced the harness on his Freightliner with a Detroit, same issue, no cruise control. He ran the wires and discovered they were not there to operate the cruise in the new harness.

Do you still have the old harness to compare with the new one? That is how he discovered the issue, along with having a copy of the wiring schematics.