I’m sorry did you find out why your ammeter was melting? I’m currently on my third and I don’t want t to actually connect this third one and waste the money. I don’t know why mine is melting. My hho system is a wire connected to an ignition on source that goes to a relay the relay is connected to the positive battery terminal, the ground, and a 30 amp fuse. The fuse goes to the fuel cell positive and the fuel cell negative goes to the ammeter positive and the ammeter negative is connected to the negative battery terminal. I know nothing about electrical works I just followed the diagram that was sent along with the hho system and I was winging it with the ammeter wiring because the diagram didn’t instruct how to set up the ammeter. Can anyone identify something wrong in my wiring description? Or what was the solution to the OP’s melting problem?
My hho system also just turns off randomly, the wire at the relay that’s connected to the fuse that goes to the positive terminal on the fuel cell loses power. Maybe it’s the relay? The relay gets warm to the touch.
