Mitch Thompson

hey everyone new guy here, not sure if I'm on the right forum, but I picked up an old tow truck with an oberg wrecker body on it (1973) and had a question on the big amber lights on top (7" amber lights) and how they operated, just on or off with a switch or light up one side or the other ( alternating I guess) can't seem to find very much info on these old wrecker bodys so any info is great, thanks in advance