I'm thinking hiker is right. But more info or a picture would be helpful.
Has it ever worked properly and now isn't??? If it never worked right,
disconnect everything and then following the page you referenced, hook it
up again and check the output. If it did work properly once, then it is a
bad rectifier. In reference to hikers picture, I would not use the diagram
on the left (only 2 rectifiers). If the rectifier with 2 wires shorts out,
you instantly put the brakes on. Had it happen to me. Now I use 3 rectifiers.
Do you know how to check the rectifiers using a multimeter??
Ralph