Please give us the model and serial numbers of the tractor. Plus all the numbers off the engine. There are some great techs on this site, but with all the political ads blocking our ESP we have no idea where to start helping you.
MTD normally puts the fuse in the neighborhood of the battery. Could be clipped to the frame above the hitch, taped to the wiring harness, etc. May have to remove the battery to find it, if the battery is under the seat.