Hi Lisa,
The Lights, Motors, Action! Extreme Stunt Show is one of my sons' favorites too and I know how disappointed they would be if it were closed during our visit. Attractions are scheduled for periodic maintenance but not necessarily closed every year for an extended period of time.
I checked the calendar for scheduled closures at DHS and don't see any attractions scheduled for anything during those months as of right now. However, keep in mind that could change between now and your trip.
You can keep a check on-line for scheduled Operation Updates for DHS by clicking
here. From there click on the month of your visit. Then click on a specific date. To the right of the daily schedule of events, you will see a section that says "Operational Updates for". If there is nothing listed, then there is nothing scheduled. However, even if attractions aren't scheduled for closures, they could close on any given day for a number of reasons.
You are welcome to check back with us closer to your trip to see if we've heard anything new regarding Lights, Motors, Action! I'll keep my fingers crossed and send some pixie dust your way that your son gets to see the show during your visit.