A couple of years ago I upgraded my 812 with a Kohler M 20 Twin. After installing the engine I removed the 812's old wiring harness, ignition switch, regulator and I replaced it with the complete wiring harness from the donor tractor which was a 20G. It ran well until this past summer where I began to have intermittent ignition issues. I parked it and began doing my mowing with my L-8. I decided to fix the 812 and now I have no spark at all. Then engine cranks but has no spark. The magneto is good as If I unplug the kill wire at the magneto I can crank the engine and both plugs have a strong bright spark. With the harness connected I can crank the engine and have no spark. I have inspected every inch of the harness looking for any place there could be grounding. The harness has never been cut or modified. Nothing found. I replaced the ignition switch (P/N19233) with a known good switch (19233) and no change. All of the safety switches in the seat, PTO clutch lever and forward/reverse lever have been jumped and there is a verified complete circuit there. There is a relay (40216) and a time delay module (P/N 40313) that came with the harness. Could one or both of these have failed? This is the seemingly last place to look for the issue. Any suggestions on how I can further troubleshoot the thing?. Thanks.