reverse lights problem

[Ranger Sport Honduras]

my mom's ranger reverse lights don't work. they worked fine untill they had to change the clutch(5spd) since then, no reverse lights for that car
i remember that once that happened, and when they replaced the clutch they worked again, now again they repalced the clutch and the lights are out. i checked the bulbs, and they are fine, is there some plug under the car, near the gear box that is unplugged?? thats what i assume, since they only fail when the gearbox gets work done, maybe the mechanic forgets to pug it or it doesnt works properly now.
soem advice here please

thanks

 

[ZBMarek]

There is a reverse light switch on the left side of the transmission. It may be unplugged.

 

[Ranger Sport Honduras]

mmm thanks im gonna check there