Painless Wiring Celebrating 30 years as the leading manufacturer of automotive wiring. Whether it be hot rod, street rod, muscle & classic car or universal wiring harnesses and accessories, Painless has your classic car/truck, off-road rig, or race car covered. Dual Battery Install With Painless Wiring Kit | IH8MUD Forum I was asked in another thread to post pics of my dual Optimas and battery kit #40103 from Painless Wiring. The yellow is a 34D/78 and the red is the 34R reverse pole for the FJ-80. The Painless system allows you to connect and switch two batteries from the cab via a 3-way toggle and two.. Painless 2013 SEMA - YouTube Click to view on Bing3:21Adrian Murray President of Painless Performance Products talks about the new Wiring the Mustang from Scratch - Painless Pro Harness and Dakota Dual Battery Setup with DetailedAuthor: Painless PerformanceViews: 8 How to - Install A Dual Battery Kit // Supercheap Auto A dual battery setup is essential to anyone who wants their vehicle to run a heavy electrical load, without being left with a dead starter battery.