Port motor starts and runs great, lights gauges etc. barely flicker when I push the start button. Everything seems normal there. Starboard motor, however, really draws a ton of current. It will stall the port motor completely if it doesn't start right away, the lights dim like an exorcism, even when it's hooked up to the charger, and the gauges go wonky (ping and bottom out completely). I thought I may have got a crappy starter from DB Electric, causing the current draw, but I swapped starters and same issue with the stbd motor, no issue with the port motor. Seems like it has to be a wiring issue with the ground or main power supply to the starter. Is the only engine ground the thin 8-10 gauge green wire? Anyone have any success with running a dedicated ground right to the negative battery cable?

The stbd relay triggers nice, and the solenoid does it's job, (still draws a ton of current jumping the solenoid) but it seems the main power cable or ground is weak or corroded. I'm torn between running a new ground, and/or tracing back the thick red power wire that runs to the starter. I see that the main power supply runs from the starter, across the port motor, and up the sidewall, likely to the Perko on/off switch that I can access from the cockpit. Does the Perko switch come apart for cleaning, or should it just be replaced if it's the issue?