I could be a ground issue as well. You can rule this out with a control test.
Hit up arrow and menu buttons together
-hit menu until you get to device test
-hit menu to get past rope switch screen
you will now be in control test mode
Throttle up. It should hold about 1700rpm. Flip on lights, heater, stereo, everything electronic. If RPM changes it is likely a ground issue.
I think there is a video on their website that goes through it.
Perfect Pass has great customer service, give them a call and they will talk you through whatever the issue may be.
Good luck!