Location of backup light switch on manual transmission a 2001 Chevrolet S10 pickup truck?

There isn't a separate backup light switch on a 2001 Chevrolet S10 manual transmission. The backup lights are activated by a switch built into the transmission itself. It's a mechanical switch that's engaged when the transmission is shifted into reverse. Therefore, you won't find a separate switch to replace or troubleshoot. If your backup lights aren't working, the problem lies within the transmission switch, the wiring, or the bulbs themselves.