The shop manual will only reference the same fundamental steps, meaning repeat the 3wV (3-wire-variable):
1. Connector not connected: This says, I have a lamp with a wall socket. The socket is out of the wall.
2. Wire out of connector: This says, I have a wire that goes up to the lamp that is not connected in a socket or a wire on the other side of the lamp is that wire pulled from the switch or connector.
3. Short to ground: This says, I have a broken filament, a bare wire grounding into the other wire. A wire snipped inside the cover you can't see the strands apart not making contact.
A. Connector not connected: How many accessories or what did you do to keep the light on without turning it off. Did you test something? So, did you take apart something and it is not reconnected?
B. Wire out of connector: When you pulled on any wires, did you pull so hard that a wire came out of a socket or a pin is not touching to break contact?
C. Short to ground: A relay is a jobber. A battery is a jobber. A fuse is a jobber. If you heat some jobber, it could cook a wire that is going into it. The jobber can break or burn a wire internally. A wire coming out of the jobber is another suspect. There is your short kind of a library full of variables that a wire can do or a jobber can fail and/or be out of spec.
No matter how you slice it, it says one of the 3wV's is your problem. You need to eliminate the two. This is like fuel-spark-compression. Eliminate the two and there is your problem.