Voltage Drop

I have a a camera, a radio, and a switch in a box on the pole going down my driveway. When I have them all plugged in, none of them work. But they all work individually. I measured voltage right before the breaker (that's also on the pole) and got 95v. I measured up by the power lines and I got 129v. What could be causing the voltage to drop like that in the 8ft of conduit that is between the two?