Trailer lights! Help

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Apr 14, 2021 | 04:42 PM

steelie green

Thread Starter

Trailering

Joined: Mar 2020

Posts: 20

Likes: 1

Trailer lights! Help

2021 Lariat. Got the new truck 2 weeks ago. Hooked up my utility trailer today and no lights. Message says.
Trailer lighting module fault.
Trailer left turn lamps fault. Check lamps.
Trailer right turn lamps fault. Check lamps.
Anyone have some information on this?
This is using the 4 pin flat plug.

Last edited by steelie green; Apr 14, 2021 at 04:43 PM. Reason: made addition

Apr 14, 2021 | 05:19 PM

Ltngdrvr

Lead Driver

Joined: Nov 2005

Posts: 8,472

Likes: 4,965

Sounds like a ground issue, most likely on the trailer.

Apr 14, 2021 | 05:31 PM

powerboatr

Cargo Master

Joined: Apr 2021

Posts: 2,022

Likes: 755

From: Texas

Quote:

Originally Posted by Ltngdrvr

Sounds like a ground issue, most likely on the trailer.

in the immortal words
from over 20 years of ford trucks...ITS almost always a grounding issue, the system is sensitive to grounds

check all of them first and make sure the lights are actually grounded.
my hauler trailer looses ground often on the LED rear light assemblies. corrosion is a tuffie

Apr 14, 2021 | 05:40 PM

chulavista

Senior User

Joined: Jan 2020

Posts: 194

Likes: 12

From: Arizona

Quote:

Originally Posted by steelie green

Had almost the exact same error messages on our 2020. We checked the trailer with another truck, and trailer lights worked. Took the truck back to the dealer, they found a plug that wasn't completely plugged in. Simple, but frustrating.

Apr 14, 2021 | 08:54 PM

2020STX250

Mountain Pass

Joined: Jun 2020

Posts: 248

Likes: 40

From: Texas

Start at the tongue of the trailer and make sure the white wire is solidly connected to the trailer frame. I've seen trailers work on one truck but not another due to the only ground path back to the tow vehicle was the tow ball.

Apr 15, 2021 | 08:18 AM

crewzer

Logistics Pro

Joined: Apr 2000

Posts: 4,334

Likes: 306

From: Mills River

Quote:

Originally Posted by chulavista

Had almost the exact same error messages on our 2020. We checked the trailer with another truck, and trailer lights worked. Took the truck back to the dealer, they found a plug that wasn't completely plugged in. Simple, but frustrating.

A good possibility. Just slide in under the back,of the truck and make sure the truck’s trailer harness is securely plugged into the back of the bumper-mount trailer connector.

HTH,
Jim / crewzer