I should probably know this, since my father was an engineer for Tung-Sol and made millions of these. On a typical 1157 bulb, which filament is normal on, and which is for brake/signal. When I rewired the car, I copied what was there, but I suspect its bass-ackwards. The shorter, lower filament is on, and the upper longer filament is brake/signal. When the lights are on, you can hardly notice the brake/signal. I hard-grounded the sockets with a wire lead. Thanks, Frank/55-C300