third brake light works others do not on 1995 Chevrolet 1500 Pickup

I checked bulbs,connections in wiring harnnes,checked for voltage under bed where harnnes splits off

Asked by for the 1995 Chevrolet 1500 Pickup
1 answer
Get a wiring diagram and see where this might be losing voltage. Find a good diagram here: http://bit.ly/mitchell_repair_manuals_online