I have a V-Box that came with an remote control and I can use the remote to go passed the set satellite position, I do not know if the G-box can do the same. Currently I do not have any limit set in my v-box nor my receiver.
But, ..... You can check if the actuator itself is at fault. Remember that the actuator itself could have limits set and I do not know anything about this actuator.
You could turn off the power and unplug your G-box and receiver. Leave the G- Box and receiver disconnected all the time while doing this.
Then disconnect the motor leads that is coming from your G-Box on the actuator.
Connect 2 wires to the actuator on the motor terminal, MAKING SURE THAT YOU DO NOT CONNECT THESES 2 WIRES TO THE REED SWITCH TERMINAL and then connect the wires to a 12 volt or 24 volt ( 2 12 volt batteries in series) to a battery.
To reverse the travel of your actuator just reverse the polarity of the 2 wires.
Do this at the dish so you can see what is going on, and if there is a bind or a stop disconnect the battery right away and see what the cause is.
I used a double pole - double throw momentary switch with center position of the switch OFF a while back to aim and adjust my dish, this way I was able to stop the dish with the switch and I was able to change directions without having to disconnect the wires from the battery or actuator. I took the receiver, cheap signal meter and a TV to the dish and hooked it straight to the dish without my V-box so I can match the dish to the arc.
Here is a wire-diagram.
Here are some pictures.


My first free dish, 7.5 feet K-tronics
