ERD50
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
Can you hook it up to a volt meter ? See if it generates voltage.
Maybe it's working, but the lights are burned out.
No, it doesn't work that way.
Check the other posts, and read the manual that was linked. This is a 'smart' charger - it doesn't put out any voltage until it senses a reasonable battery voltage. It checks polarity, checks for voltage. Won't attempt to turn on if it doesn't look right.
This is for keeping a battery topped off, not really for charging a dead one.
-ERD50