Error 05, but still clicks

I have an 08 that sat for about 2 months and now it’s showing error code 05 when I press the throttle. I have read that would be caused by the main contactor not engaging but I hear a click from the right side of the dash when I press the throttle the for the 1st time and then again when I engage the parking brake. I don’t believe the click Is as loud as it used to be but not sure. Also my low beam headlights stopped working. Anyone have any suggestions on what/how to trouble shoot?

Thanks
Derrick

Something in the throttle. Either check voltages on throttle wires at controller, or see if aggressive cycling of throttle (power off) will temporarily clear the error. May need cleaning.