A simple trick to finding a short is to replace the blown fuse with a pair of spade terminals, then use small jumper wires to connect them to a 12 volt light bulb. A brake light bulb works well. When the circuit is live and the short is present, the bulb will be full brightness and hot so be sure it's not laying on the carpet or against a plastic door panel. Now you can unplug electrical connectors and move things around to see what makes the short go away. When it does, the bulb will get dim or go out.
In this case the first suspect would be broken or frayed wires between the door hinges. There's two wires in each door for each lock. They switch which one gets 12 volts depending on which way it needs to move. One gets 12 volts and the other one gets grounded. If a lock wire is shorted to a ground wire it will still work properly in one direction when it is supposed to be grounded, but it will blow the fuse when it is supposed to get 12 volts in the other direction.
Oct 26, 2013 at 4:39 AM
