After many hours of dismantling and cleaning I came to the conclusion that my ECM has an issue. I get a signal from the switch to the ECM but nothing out to the solenoid. All of the wires involved show continuity and look good. Connectors are clean and undamaged. So, for now I centered the blade and don't have an angle function. Thanks for the ideas and help with the problem. The wiring schematics are a huge help.
ECM failure is very unlikely, but possible. Typically, ECM failure occurs when welding with the ignition on. Before thinking badly about the ECM, try installing a new K788 wire directly from the ECM to the left solenoid. Disconnect the old wire. If this does not help, then you can install an additional toggle switch that will switch the K788 wire to K789. This will be much cheaper than changing the ECM, you will only need to get used to the controls)
Yeah, I kinda ran out of time and patience for now. I'll dive into it again at some point. I thought of maybe a 2 pole momentary switch to the solenoids?