Thanks all who replied. I ended up investigating some more and noted that the wires inside the nut that melted were barely connected. I checked the elements resistance in the water heater and visually checked the electrical wire going to the breaker box. Everything looks clean with no indication of an issue besides that wire nut. I’m concluding it was a loose connection and hoping that is right. I redid the connection and installed a fire alarm right above the water heater. I then let the water completely warm up and checked the wires (after turning off power) to make sure they were not hot. So far it is all working as expected.

I’m confused if this is a plumbing or electrical thing. Would the short be in the water heater or in the wire before it?

Added the diodes today and it’s all working great! Thanks for helping me understand this!

Thanks! I think that is what I was originally trying. By adding the hazard “3” connection to both sides of the blinkers it ends up connecting them so that whether I use blinkers or hazards it’s all the same. I’m going to do some more debugging with a multimeter and see if I can understand the switch more. I’ll probably just end up getting diodes and wiring it like this diagram with diodes. Just bothering me that I might be missing something.

If you ignore the hazard switch in the image I posted that is what I have wired. 1 & 3 on the blinker switch are connected to blinkers on each side. I got lost when the hazard came into play… Do you understand what the directions are saying with “+ switch negative”, “negative led light inside switch”, etc? I looked at the diagrams you linked but it’s hurting my brain even more at this point :)

Yeah that’s the only thing I can think of too. I don’t think the kit came with diodes which made me think I was misunderstanding something. Thanks! I will have to go with this unless there is another trick.

Edit: ended up going with diodes and it works great!

Looks like she was from Kansas. There are more articles out with details.

I too am curious about this. Does each instance have its own copy of the data from the other instances? How does it stay in sync?