Turn signals not working, blowing fuse

Keep in mind it can be a short hidden in the harness. If for example you short something to ground and heat up the wiring the insulation can melt and cause "cross connect" to other wires in the harness.

Sometimes you need to take "extreme" measures. If you are certain that you have it down to the daisy chaing wire that feeds off the fuse to various loads, pick one "in the middle" and cut the wire far enough from the connector that you can splice it, or pull the terminal out of the connector and cut it there to solder back later. If the short is in the now isolated section from that point to the end of the "daisy chain" at least you have cut it down some.

Also bear in mind "pinched wires." I know you isolated the rear harness but a good example is the rear harness where it goes under the rear seat and into the trunk. That is an easy place to be pinched.