A lot of people have a misconception of placing sweet corn together with charcoal and barbecue together. Most of the time, corn cob end up burnt and discarded.
The fastest & smartest way to BBQ sweet corn is
1) Wrap corn in aluminium foil
2) Place corn on top of BBQ grill (Not under grill together with Charcoal)
3) Cover with aluminium tray for 5-10 minutes
4) Flip corn and cover with aluminium tray for another 5-10 minutes
5) BBQ corn is ready to be eaten!