97 T800 Turn Signal Issue (and one other lighting issue)

This KW is a bit more sophisticated than my old Mack, so I'm sure I'll be better off asking for advice rather than replacing the parts I think it needs.

My turn signals (and flashers) are working at the moment, but after just a couple minutes with the flashers on, they will lock up and stay on until cancelled. Once that happens, my turn signals will just stay on too, if I try to use them. I can simulate turn signals, turning the switch on and off, but obviously that's not a good idea. Do I have a flasher relay getting hot and seizing, or is it my switch on the column malfunctioning, or...?

Also, the outside two (of four) tail lights on my equipment trailer aren't getting full power from the truck, but I cannot find the issue. The same four leds light up in each bulb, and I did trying replacing one of them. Those two bulbs are wired to my clearance (cab) light switch, but my cab lights are working. I don't think they should be wired to the cab lights, but that's another issue. The brake and turn signals work just fine on the trailer, and all other clearance lights and the inside two tail lights work properly too.

The truck has all led lighting but just the rear panel on the trailer has them. I'm starting to wonder if that could be an issue.

I'm off to move a piece of equipment, but any help will be very much appreciated!

 

Thank you very much for the suggestions! Now that I have a day I can work on this at the yard, I will do so and report back.

If a mod can move this to a more appropriate section, that would be great!