Configure Bluetooth HC - 05 with Arduino Mega 2560

You will be better off forgetting about the LED, and addressing the real problem.

You might find the following background notes useful

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino