Can any one tell me why I lose volts when I run a 24 volt bttry through a cntrl box w/ switches & how 2 fix it?

This sounds like something you have to troubleshoot on your own, since I don't know the exact setup. Check the voltage at the solenoid when the on is pushed, compare to the solenoid spec for minimum coil voltage needed. If the switch is not super-tiny and the solenoid doesn't need huge current, I'd suspect the switch is defective or your box wiring is messed up. Note that soldered connections are better than just twisted ones. The extra resistance of a switch and a few extra feet of wiring in the box, compared to the 64 feet of wiring that worked, shouldn't make much difference, and the extra current drawn by the LED should also be insignificant.