nogoldformarfa wrote:
For some reason out of the blue the very bottom light in the taillight array (I am not 100% sure what it is I think its the brake but I could be wrong) does not light up on either side.
If you're in North America, that's not supposed to light up. If you remove the tail light housing from the vehicle, you'll see there isn't even a bulb in that position. If you're in Europe, that part of the light may serve as the rear fog lights but I'm not entirely sure.
nogoldformarfa wrote:
Moving to the trailer wiring I think I may have a problem there as the harness is one of those 4 link ones with wires to the tailights and then one super long wire that goes form the harness to the battery.
At the end of that long wire there is a fuse and then it is secured to the positive terminal of the battery. The fuse was blown so I though oh ok that must be it but every time a replace the fuse it blows as soon as I reconnect the positive battery terminal.
My latest thought is that it must be the ground for the 3rd bulbs. I think they are grounded in a separate place than the other bulbs but I do not know where that is. Does anyone know?
Looking up the pinout for a 4-pin trailer connector, it appears to be:
white - ground
brown - taillights
yellow - left turn signal/brake light
green - right turn signal/brake light
If the white wire is connected to the positive battery terminal, that's a problem. The other end probably connects to the body of the trailer, which is grounded through the trailer hitch (though not 100% reliably grounded through the hitch; you'll still want a ground wire connected).
So if that's the case, you have positive -> fuse -> ground, which would explain why the fuse keeps instantly blowing.
nogoldformarfa wrote:
My latest thought is that it must be the ground for the 3rd bulbs. I think they are grounded in a separate place than the other bulbs but I do not know where that is. Does anyone know?
Is it ok to just ground them on bare metal in the housing for the taillight? If I do that do I just use the black wire going into the taillight connector cut it and then ground it to bare metal? Do I do that for each side? Is this idea insane?
I would think the tail lights would be grounded to a metal surface on the trailer, as long as that metal surface has a good reliable connection to the metal where the ground wire is connected.