Power Expander Problem

This is a stand in until our club account is activated. We have been using a power expander on our robot, but the motors connected to it will not move. We have the status port plugged in. When it is plugged in we get the red blinking light (green if not plugged in,) which according to the forum should be ignored if the status port is being used. Our code looks like this:
task main()
{
//User control code here, inside the loop
//Controler
while(1)
{
motor[drive1]=vexRT[Ch2];
motor[drive2]=vexRT[Ch2];
motor[drive3a]=vexRT[Ch3];
motor[drive4b]=vexRT[Ch3];

}
}
Drive 1 and drive 3a do not work.

How exactly is the power expander hooked up to the robot? Also, what is the configuration of the robot (#pragma statements at the top of the code)?

Please double check the wiring to this guide, just to make sure it’s not a wiring issue: http://content.vexrobotics.com/docs/instructions/276-2271-INST-0412.pdf