The search function doesn't seem to work.

The feature is a little different than the old version.
What are you searching for? And what did you get when you searched for it.

I search for different topics, such as "generator" or "overcurrent" or "smoke alarm". Never get results.

Well I am stumped Nick. I get results on every keyword you mentioned. Are you selecting a specific date range or forum?
The default date range is newer than 1 week.(I need to figure out how to change that) Which at this time will show something on all the keywords.

Are you getting a completly blank page or

Try this. GOTO your preferences and turn on the left side and try the simple search window at the bottom left of the screen.
Lets stick with one keyword "generator"