Can't say for sure, but I have seen switches with separate connections for each side of the car. One would think there would be a terminal connected to a relay, then the relay would be connected to the circuit and to the load (lights, etc.). But, I've seen separate terminals for each fusible circuit, ie: right side of the car versus left side.
Check the switch and see if any terminal is touching another and causing the short. But
BE CAREFUL, the terminals are
hot even with the ignition switch off in most cars. You can cause a real fireworks show if you're not careful. Make sure you've got some spare fuses on hand...you'll probably need 'em....ask me how I know this!
If you can't find the problem in the switch, disconnect one terminal at a time to troubleshoot. If something else goes off and stays off, then that's not the bad circuit. Eventually, you'll get to one that makes no change to your problem - THAT'S THE ONE! Then all you've got to do is figure out what's wrong with that one...I'd bet it's touching another terminal and causing a back circuit, short, or ground problem.
Frustrating as hell, I know, but I don't know of another way. Start at one end of the circuit and test until you get to the end of the circuit...jumping around will cause your to lose your mind...don't ask me how I know about THAT one either!
Don't forget about the fireworks show...it will happen...trust me!
