The light before leaving
Text: an original contemporary personal account-style practice extract.
Before cycling to my friend’s house, I checked my bicycle lights in the hallway. The back light did not come on, so I removed the old batteries and fitted two fresh ones. When I pressed the switch again, a red circle appeared on the wall.
I was eager to leave, but Dad asked me to check the front light as well. A few minutes later, both lights were shining and I wheeled the bicycle outside.
Identify the change the writer made to the back light before testing it again.