It seems that MTD only publishes that info in service manuals which they offer for sale on their website. These manuals cover several models in year groups and are geared towards the repair shop. check it out, it may be worth ordering one if you cant trace out the circuits with a meter.
A fried harness can be rebuilt with patience, a sharp utility knife,lots of new wire of the appropriate guages, crimp on terminals and lots of tape to put it all back together.
I usually nail down the old harness on a piece of plywood large enough to fit. tack down each connector and add pins to guide each wire into their own branches. I will look like a crazy stick figure drawing (which you will probably find in the owners manual that can be downloaded at no charge ). make note of wire sizes and color right on the plywood at each connector location. You now have a wiring jig just like the factory. Now begin slicing each conductor out of the melted mess keeping them in the proper routing positions. replace each conductor with the proper wire , double check it all with a meter. then wrap it back up with tape and harness tubing.
R Pearson
Robert F. Pearson Sr.
June 2007