The instructions give you two wiring options. I went with method 1, starter wired directly to the battery side of the starter solenoid and I did not install a cut-off switch. I've been running it that way for many years without any problems. From their website, "Method 1 is recommended because it is simpler, doesn't require a diode, and extends the life of the remote solenoid." I tend to listen to the manufacturer on matters such as this, as they know their product better than anyone.