I'm sorry to say that I don't have a wiring diagram for you but I may have a solution to your rodent problem….
Ammonia. I had problems with rodent also. I had tried all sorts of remedies and then I realized that I had been using ammonia to keep bears out of my garbage and thought I would try it around my machine. I found some old plastic vitamin bottles, placed rags inside, and drilled some holes in the lids, and then poured some ammonia in the bottles. I placed these bottles in the engine compartment at areas that the rodent could enter the machine. I remove the bottles before operating and renew the ammonia and replace the bottles when done.
The ammonia makes the rodents think there is a predator near the machine and therefore avoid it. It's a little bit of a hassle but well worth it.