The lights shining on the Mosgiel sign were turned off about six months ago because they were starting to fail, Rotary Club of Mosgiel member David Brown said.
"It was looking quite spotty — some lights on and some lights not working," he said.
New LED floodlights had been given to the Rotary club, as the sign was a club project.
Members had waited for the right time to replace them, so the sign was able to be cleaned in the meantime, Mr Brown said.
The new lights were installed this week and on Monday were switched on.
Residents were pleased, as the sign had become a bit of an icon, he said.
"We’ve certainly had a few calls asking why they’re not on."
Mr Brown said vandalism of the sign was a problem and the club hoped to install security measures soon.
