Birth of the Blue Missile
I decided to set up a rainy day project for the weekend, hasn't started raining yet, project done.
There are a half a dozen major control centers (relay modules) in the Missile. The one for the front grill and hood subsystems has been wonky for a while. It was the only one I actually soldered relays directly into circuits without relay sockets. Guess where the problem was.
So I made a new board with relay sockets and then transferred all the wiring to the new board, installed the relays, and plugged it back into the car.
All problems have been solved.