12V question. Can anyone tell me what this is?

[Wisco Dude]

This red thing is hooked up to the positive battery cable. It looks like it was attached to the frame at one time but rusted off. When I moved it a little bit, I could hear a clunking noise from somewhere towards the back of the trailer. Within a few days after that my battery went dead, despite being hooked up to shore power. (Battery had been charged every month all winter long and was fully charged). Is it some kind of a disconnect switch, fusible link, relay or something else? Just wondering what this thing is, what it does, what effect it might have had on my battery and 12v system, and whether I need to replace it.
Thank you!

[houstonstroker]

Looks like a 12 volt automotive re settable circuit breaker.

[oldmanAZ]

There appears to be a 'loop' at the right side (as seen in my screen) as though it is a hinge for the top. Can you pop the top open and see what's there?

[Iraqvet05]

Circuit breaker. If it isn’t passing voltage, then replace it.

[Wisco Dude]

Originally Posted by oldmanAZ

There appears to be a 'loop' at the right side (as seen in my screen) as though it is a hinge for the top. Can you pop the top open and see what's there?

I will do that this weekend when I'm down there and will take a picture to post on here. I greatly appreciate your help, guys. Thank you.

[Wisco Dude]

Originally Posted by Iraqvet05

Circuit breaker. If it isn’t passing voltage, then replace it.

It looks like they are only about $10, so I'll just go ahead and replace it. I assume since the trailer is 50A, I'd get the 50A breaker, right? (probably a dumb question, but I guess it's better to ask a dumb question than screw up the trailer). Thank you.

[us71na]

Originally Posted by Wisco Dude

It looks like they are only about $10, so I'll just go ahead and replace it. I assume since the trailer is 50A, I'd get the 50A breaker, right? (probably a dumb question, but I guess it's better to ask a dumb question than screw up the trailer). Thank you.

Most likely only your AC system is 50 amp. You likely want a 30 amp breaker or fuse on your battery. Note that you need a 12 volt circuit breaker not a normal house 120 volt type circuit breaker.

[Grumpy]

Clunking noise could have been the brakes activating, thus the dead battery. It might be a circuit breaker that was put in for the breakaway switch for some reason. I would definitely trace it before I would do anything else.