last week of the season last year i was mowing and i broke the speed control lever off. with this lever broken you could not start the mower. so i would flip the seat up and push the safety switch tab down with my fingers and start the mower. it would just operate at any speed and i just used the steering levers to operate it. well after a while this started not to start the machine. so i bought a new safety switch and installed it and a new forward speed lever and still doesnt want to start. i then took the switch off and taped it down thats what i did on my 2002 walker and it works every time. i then bought a new battery and took all the fuses out and checked them and then traded ignition switches between the machines. i traded all the relays over between the machines. the 04 when i discounted all the relays the plug in's were very dirty at the connectors. the 02 still started right up and the 04 will not turn over. i jumped the starter with a screw driver and it makes noises but it no longer turns all the belts. i also was trying to start it with the tape off the saftey switch and just pushin it down with my fingers and at the same time i happened to touch it to a pulley on the belts and while turning the key it tried to start. can some help me and figure out what is wrong? maybe the ecm is fried??? or just the dirty relays???? poor ground???