When switched to LINE all circuits work. When switched to GEN, only circuits BDF work. ACE goes dead. I tested ACE with a volt meter and a clamp multimeter. Circuit A, for example draws 3A when on LINE. Switching to GEN drops it to 0.1- 0.2A.
BDF work great. Example, the 20A circuit it's drawing 11A from the generator during a test to run an air-conditioner. The other two 15A circuits draw 1.5 and 3A.
Generator is a 7000W Westinghouse.
I'm tempted to uninstall it and take it apart to test with a multi meter, but, I'd rather not.
Update: it looks like the bottom set of blades run the circuits in question. They are connected to a black wire on the side.
I was trying to see on the box looking for a lose connection, but, unfortunately, it's riveted, so access is limited at best.
Updated image: the box outside: