RV trailer running lights wiring issue
I have a camping trailer from 1978, and while getting ready to go on the road again I noticed the running lights are acting wonky. I think it must be a wiring issue but don't know much about electrical systems. The plug-in to the tow vehicle is newer, just a couple years old, but I think the rest of the wiring is original.
My trailer is equipped with lights as follows: a yellow one on each top front corner (2 total), a yellow one on each top side corner (2 total each side), 5 red ones along the top rear, and 2 larger red rear headlights. With the tow vehicle's headlights on, all trailer running lights come on except the two red ones on either side of the center top rear light. When I first tested the left blinker, not only did the left rear headlight blink but all the lights along the top on both sides were blinking. That issue seemed to resolve itself, and now when the left blinker is on the left rear headlight and the two lights on the top left rear corner blink, which seems right to me. With the right blinker on, however, only the right rear headlight blinks (and it doesn't blink very noticeably, as the light doesn't go all the way off it only dims on the off-blink). This is not ideal but it's something I could live with if I had to. However, the real issue is, when I step on the brakes no additional trailer lights come on. I wonder if the two lights on the top rear that never come on are supposed to be the brake lights? If it were just that these aren't coming on I would replace the light fixtures to see if that resolved it, but what does happen when I brake is that the left rear headlight and two lights on the top left rear corner go out completely. All this makes me think something is up with the wiring.
Does anyone have ideas about what specifically might be going on or how to address it?
My trailer is equipped with lights as follows: a yellow one on each top front corner (2 total), a yellow one on each top side corner (2 total each side), 5 red ones along the top rear, and 2 larger red rear headlights. With the tow vehicle's headlights on, all trailer running lights come on except the two red ones on either side of the center top rear light. When I first tested the left blinker, not only did the left rear headlight blink but all the lights along the top on both sides were blinking. That issue seemed to resolve itself, and now when the left blinker is on the left rear headlight and the two lights on the top left rear corner blink, which seems right to me. With the right blinker on, however, only the right rear headlight blinks (and it doesn't blink very noticeably, as the light doesn't go all the way off it only dims on the off-blink). This is not ideal but it's something I could live with if I had to. However, the real issue is, when I step on the brakes no additional trailer lights come on. I wonder if the two lights on the top rear that never come on are supposed to be the brake lights? If it were just that these aren't coming on I would replace the light fixtures to see if that resolved it, but what does happen when I brake is that the left rear headlight and two lights on the top left rear corner go out completely. All this makes me think something is up with the wiring.
Does anyone have ideas about what specifically might be going on or how to address it?
