No trailer marker lights - ASAP
Thread Starter
|
Senior Member
Joined: Sep 2010
Posts: 121
Likes: 1
From: North Carolina
No trailer marker lights - ASAP
Morning,
2008 F150, 4wd, 4.6, with factory towing harness
Everything was good and the past few weeks I had to wiggle the harness under the truck back at the trailer plug for the marker lights to come on. (stop lights and blinkers work on truck and trailer) Now they don't work at all, I'm getting no power to the plug for the trailer marker lights. (all truck lights work fine). I replaced the trailer marker light relay and still nothing, am I missing a fuse somewhere?
Thanks
2008 F150, 4wd, 4.6, with factory towing harness
Everything was good and the past few weeks I had to wiggle the harness under the truck back at the trailer plug for the marker lights to come on. (stop lights and blinkers work on truck and trailer) Now they don't work at all, I'm getting no power to the plug for the trailer marker lights. (all truck lights work fine). I replaced the trailer marker light relay and still nothing, am I missing a fuse somewhere?
Thanks
Global Moderator &
Senior Member
Senior Member
Joined: Aug 2007
Posts: 7,890
Likes: 61
From: Among javelinas and scorpions in Zoniestan
My 2014 F150 uses both a fuse and relay for the trailer battery charging circuit, but as I recall, there's nothing special for the trailer lighting. It's just powered off the same circuits as the truck's lighting. The same was true for the trailer lighting when I had my 2005 F150.
From your description then, I'd say you have a possible bad connection or broken wire at or near the trailer plug.
- Jack
From your description then, I'd say you have a possible bad connection or broken wire at or near the trailer plug.
- Jack
Senior Member
Joined: Oct 2002
Posts: 7,295
Likes: 125
From: St. Louis (Out in the woods)
am I missing a fuse somewhere?
1. Check to confirm that F10 is passing power (ALWAYS HOT).
2. Verify that the trailer backup lamp circuit works (Ign switch in RUN, shift lever in Reverse, 7-pin connector).
3. If both of those check out, you'll have to verify the trailer running lamp relay actually energizes (PARK/HEADLIGHTS on).
4. I f all of those check out, you'll have to trace the circuti from the rear connectors back forward and look for the open circuit. BR/WH wire.
From your description then, I'd say you have a possible bad connection or broken wire at or near the trailer plug.
Thread Starter
|
Senior Member
Joined: Sep 2010
Posts: 121
Likes: 1
From: North Carolina
The trailer running lamp relay is supplied by fuse F10 in the CJB (shared with the trailer backup lamp circuit).
1. Check to confirm that F10 is passing power (ALWAYS HOT).
2. Verify that the trailer backup lamp circuit works (Ign switch in RUN, shift lever in Reverse, 7-pin connector).
3. If both of those check out, you'll have to verify the trailer running lamp relay actually energizes (PARK/HEADLIGHTS on).
4. I f all of those check out, you'll have to trace the circuti from the rear connectors back forward and look for the open circuit. BR/WH wire.
Highly likely based on what you reported.
1. Check to confirm that F10 is passing power (ALWAYS HOT).
2. Verify that the trailer backup lamp circuit works (Ign switch in RUN, shift lever in Reverse, 7-pin connector).
3. If both of those check out, you'll have to verify the trailer running lamp relay actually energizes (PARK/HEADLIGHTS on).
4. I f all of those check out, you'll have to trace the circuti from the rear connectors back forward and look for the open circuit. BR/WH wire.
Highly likely based on what you reported.
Senior Member
Joined: Dec 2006
Posts: 43,540
Likes: 819
From: Joplin MO
Refer to post #3, that's the troubleshooting flow.
Trending Topics
Senior Member
Joined: Oct 2002
Posts: 7,295
Likes: 125
From: St. Louis (Out in the woods)
`A "bad ground" would affect BOTH the running and the stop/turn lamp circuits. Next...
Really, if you are not trained or skilled in electrical troubleshooting, it's probably not in the interest of all if you try as you're just giving put erroneous information that only confuses things.
Really, if you are not trained or skilled in electrical troubleshooting, it's probably not in the interest of all if you try as you're just giving put erroneous information that only confuses things.