artdevilish

2014 Lariat F150. Boat trailer lights went out. Using 7 pin. Works fine on wife's truck. Have power coming to all ports of 7 pin except the one labeled (+) on the 7 pin plug cover diagram.

I figure it must be the ground. Also, checked fuses 67 and 73. How do I fix? Where is ground wire connected?
THanks for the help.

artdevilish

hellooooo...anyone?

DirtDawg

Did you install the relay intended to supply charging power when towing travel trailer which has a "house" battery? Mine was uninstalled (inside bag in glove box). Wouldn't think your boat trailer needs that for turn/stop/running lights but depends on how it was wired. I installed the relay in mine before even towing, so I had no issues with even a simple utility trailer.

artdevilish

haven't installed, but been pulling boat for 4 months with no issue. until yesterday.

whitescrew77

Is your truck wiring harness damaged, fuses good, metal spades in the plug clean, good contact to trailer plug?

artdevilish

yes. all in good shape. Truck has 14K miles on it.

CCR90

You must still be under warranty then? I'd just let the dealer deal with it unless you need it right now.

Do you own a multimeter to check and see if you have ground on one of the pins? Check your pin 1 for good continuity.

artdevilish

Update. The trailer brake lights work. Turn signals and backup lights. Just the running lights won't work. I have checked 67&73 fuses under hood. Anymore suggestions?

CCR90

Try following that wire out of the plug and check for nicks/broken wire or corrosion in any connectors along the way

artdevilish

Looks good. I wish someone knew the fuse number. Dealership will get it Monday.