We tow a Chevrolet Avalanche (same chassis as a Suburban) with our motorhome and in ten thousand miles we've never had an issue using the Brake Buddy.
Make sure you have a taillight wiring kit for your towed vehicle and your ignition is in the locked position, gear **** in park, transfer case in neutral. If you are towing a two wheel vehicle drive vehicle there may be some slight change in requirements. Check your owners manual.
You should consider a rechargeable jumper battery box to power your Brake Buddy or install an auxiliary battery. We used to tow a trailer and this system is a dream come true compared to that. I have a hard time even noticing that the tow vehicle is back there. In fact I have to check mirrors and rear camera to be sure it's still there.
Smooth sailing!!