What the?

[rick_ca]

went to hook small utility trailer to 18 ram 5.7 on checking trailer light not a thing, pulled covers and checked bulbs all good. Checked for volts nothing suspected wire damaged inside frame so rewired still nothing. Sitting in truck thinking WTF is wrong and pressed the tow/haul button frikking lights work WTF again why is the 4pin activated with the tow/haul switch can see the need with the 6pin but not the 4pin.

 

[kad]

I've no first hand experience with the 2018s but I don't think that's right. Both the 4 and 7 pin connectors have power any time the truck is in ACC or better on my 2014 and I think the 12v line in the 7 pin is on even when the truck isn't. I'd have the dealer take a look.

-K

 

[crash68]

^^^ what he said
Shouldn't even need to have the truck on at all. I'll turn the hazards on to check the trailer lights. 4 and 7 pin are both powered by the same outputs (turn, stop, running) from the truck and the 12V in the 7 pin stays hot all the time.
It would be a major safety issue to tie operation of the trailer lights to the Tow/Haul button.

 

[Thendrix]

I thought ground problem until you said everything worked in tow haul. I would say take it to the dealer. I wouldn't think they would make the button control the lights. Seems to me if you had to be in tow haul mode for the lights to work then connecting the trailer would make it switch to tow haul and you wouldn't have the option to turn it off. Lots of liability there.