All my prior trailers with brakes have been hydraulic 'surge' type. We've just purchased our first trailer with electric solenoid brakes. I'm concerned about how to 'test' the electric breakaway cable and switch. I see that some simply pull the cable and pin to confirm the brakes activate at full power. I also see that activating the brakes in this manner while the tow vehicle is plugged through the 7 pin connection can back-feed trailer battery power into the controller and damage it. Is there a preferred manner to test the operation? When hooking up, or disconnecting at the site, is it prudent to leave the 7 pin for last on the chance that the e-brake cable and pin might be snagged and pulled out, possibly frying the brake controller?