I used the same instructions and mine works perfectly. Which connectors are you using? On my E60, it would turn off and on if I hit a hard bump because the connector didn't have a snug fit.
What issue are you having?
Current: 2016 Silverstone M5, 2014 Anvil WW Jeep Wrangler
Previous: 2013 Monte Carlo Blue M5 (ED on 9/1/12), 2009 Carbon Black M5, 2006 Silverstone M5, 2003 Sterling Grey M5, 2000 Anthracite 540i6, 1998 Jeep Grand Cherokee 5.9Ltd, 1990 Eagle Talon TSi AWD, 1978 Mazda RX-7