WHere is the fire selector switch on the egrip upgrade kit for the us army paintball markers?

Assuming the upgrade kit is the same as the factory fitted eGrip then the following should be correct:-

1) To Turn ON the E-Trigger to normal operation – Ready To Fire:Without holding the trigger: Use a small object like an allen wrench to press and hold the power button (for about 5 seconds) until the green LED light comes on and then release the power button. Your marker is now ready for normal operation in the SEMI-AUTO Firing Mode: 1 pull of the trigger fires 1 time (This is the Factory Default Firing Mode Setting).

To select a new firing mode: With the electronics turned on,each press / release of the power button will change the firing mode to the next firing mode in the menu: (the LED will flash 1, 2, 3 or 4 timesto identify the firing mode you have selected).

THE 4 FIRING MODES ARE:
Default firing mode:1) SEMI-AUTO = 1 pull / release of the trigger fires 1 time. 1 flash of the LED light indicates SEMI-AUTO mode.

Press mode button to get: 2) TRIPLE FIRE = (3 shots in 0.25 seconds for one pull of the trigger). 2 flashes of the LED light indicates TRIPLE FIRE mode.

Press mode button to get:3) FULL-AUTO NORMAL = (12 shots per second): To fire in Full-AutoNormal mode you must pull the trigger 4 single pulls within 1.00 second and hold the 4th pull to fire 12 shots per second until you release the trigger). 3 flashes of the LED light indicates FULL-AUTO NORMAL mode.

Press mode button to get:4) FULL-AUTO FAST = (15 shots per second): To fire in Full-Auto Fastmode you must pull the trigger 4 single pulls within 1.00 second and holdthe 4th pull to fire 15 shots per second until you release the trigger). 4 flashes of the LED light indicates FULL-AUTO FAST mode.

Press mode button to get:1) SEMI-AUTO (Default firing mode as above).