Sounds like you might have a bad relay solenoid switch that is supposed to energize the circuits when you start the combine. They are located in the fuse compartment of my l2 combine. If you have a voltmeter you can test them to see if they are working. If not, you could short the input and outlet to see if the switches will then work. Replacement should then solve the problem. Another cause could be an open connection, either a plug or damaged wire. Corrosion on the connections could cause these symptoms. Checking with the voltmeter along the line to the switches can isolate where the problem exists.