My Maxi Light Tower shuts off after 45 seconds.
If your light tower will run for 45 seconds and then shut down, your SLS system is not seeing any output voltage from the generator. You can test this by starting the unit and checking for voltage at the main breaker.
If no voltage is found;
Check the wiring to the breaker from the generator.
Check the capacitor in the generator under the cover.
Test the Generator end.