hi, new to the forum and had an issue with my AC S turning off the lift and tilt valves. so I went to search these forums. I started with the lift actuator and switched that with the tilt, code stayed the same. Then I started running continuity test on the wiring and found a short to ground on the1500 and 1600 series wires. I followed that uphill to the main harness, The 1740 wire, was shorted to ground on the main harness found a relay that I thought was bad up on the back right side zip tied to the wire hangers going up to the dashboard. Replace that seeing as how unplugging it stopped my short to ground… No joy. (btw anyone know what it's for? can't find it in the service or parts manual) Now here I am thinking I have to replace the main harness, $1500 and God knows how many hours of work. after two full eight hour days, I finally went to the back of the machine and clean my grounds to the starter and body…… guess I can go to work today… Codes gone. So the moral of the story is KISS start with the simple first!!!!