hi big joe. i have done alot of trial and error, and have two 85s one 86 one 87. with different setups. a b.b.er named B.C. helped me the first time. just looked at my extra taillights. the pre -85 brake light bulb slots (3 different sizes) in the taillight housing are in a different location than the 86+. with the circut board switched and the white bulb holder installed i believe the contacts do not touch the circut board where they should. even if you remove 1 or 2 of the little black pins on the taillight that hold the circut board. this is where you have to build a metal bridge to offset the (i believe inward contact) toward center of car back and up to make the proper connection. i may not be great at explaining but have done it. summary not worth it, my solution as stated earlier=move wires, get correct light. hope this helps