The backup light switch, which is screwed into the drivers-side side of
the transmission, went bad on mine a while back. It's brass with 2 wires
going to it, I think you need a 19mm (or some other large metric size)
socket to get it out.  It was about $10 for a new switch.  This is
assuming you have a manual transmission, I don't know about the
automatics.

dave
dave@251.org