The brake lights ground thru the tailight circuit & vice-versa, an 1157 bulb has 2 fliaments but only one ground(the bulb base)don't ask me how I'm no engineer I just know it does.


My \'64\'s in the Gallery
Pictures in my Photobucket
1964 C10 Custom Cab 350/700R4
1964 Suburban 350/700R4
1979 Ford F350 4x4 400/c6