Notices
1999 - 2016 Super Duty 1999 to 2016 Ford F250, F350, F450 and F550 Super Duty with diesel V8 and gas V8 and V10 engines
Sponsored by:
Sponsored by: Real Truck

Trailer plug question

Thread Tools
 
Search this Thread
 
Old Aug 11, 2017 | 07:36 PM
  #1  
mattymax's Avatar
mattymax
Thread Starter
|
Fleet Mechanic
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Mar 2006
Posts: 1,519
Likes: 133
Trailer plug question

7 pin connector on a 2008 F-350
I need to make my trailer hot all the time cause I want to put emergency lights on the back for when I'm parked doing a job.
What wire is switched with the key ?

Plan on a line off battery with a 15a fuse in line back to the connector. I just don't know what pin to go to

Matt
 
Reply
Old Aug 12, 2017 | 08:04 AM
  #2  
danskool's Avatar
danskool
Go Bills !
15 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jan 2008
Posts: 2,778
Likes: 65
From: Buffalo, NY
Club FTE Gold Member
https://images.search.yahoo.com/sear...f&action=close


Every time I work on connectors, I go to yahoo, Type in 7 flat wire diagram, click images. A wealth of pictures to pull up with diagrams.


You may have already a hot wire back there on the connector, You trailer just might not be wired for it, There might be a wire there to charge the battery for the emergency battery .
 
Reply
Old Aug 12, 2017 | 08:27 AM
  #3  
SuperDutyScaler's Avatar
SuperDutyScaler
Lead Driver
15 Year Member
Liked
Loved
Community Favorite
Joined: Nov 2008
Posts: 8,447
Likes: 70
From: South Jersey
Looking at the seven pin on your truck the top right terminal is POSITIVE 12VOLT the flip up lid also shows that
 
Reply
Old Aug 12, 2017 | 01:48 PM
  #4  
Chuck's First Ford's Avatar
Chuck's First Ford
Postmaster
Joined: Jul 2015
Posts: 4,392
Likes: 22
From: very South Texas
as above.. Ford, the power is only there with the KEY ON....

its called "Trailer Charge" line. for charging a trailer battery. but can be used for many things... also. it is limited to 20 amps... MAX
 
Reply
Old Aug 12, 2017 | 04:31 PM
  #5  
mattymax's Avatar
mattymax
Thread Starter
|
Fleet Mechanic
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Mar 2006
Posts: 1,519
Likes: 133
Okay thanks. According to the trailer place ford does not have hot at connector when truck is off. I will run a line and replace the power on line.

Matt
 
Reply
Old Aug 13, 2017 | 12:57 PM
  #6  
fordman19762003's Avatar
fordman19762003
Cargo Master
20 Year Member
Liked
Loved
Top Answer: 1
Joined: Jul 2003
Posts: 3,357
Likes: 250
Honestly, I wouldn't want my emergency strobes wired into the key because then you have all the other acc. powered up too. My tandem dump trk has the beacon lights wired to the key and I have to manually turn off the radio, fan, etc.. so they don't run also. It would be nice to just shut the truck off and flip the switch to run the strobes.
 
Reply
Old Aug 13, 2017 | 01:53 PM
  #7  
MisterCMK's Avatar
MisterCMK
Fleet Owner
20 Year Member
Photogenic
Photoriffic
Liked
Joined: Mar 2003
Posts: 24,724
Likes: 74
From: Blue Hill Township
Club FTE Gold Member
Best bet is to put a battery in the trailer. Sure would suck to run the truck down because the trailer is hooked up
 
Reply
Old Aug 13, 2017 | 03:11 PM
  #8  
mattymax's Avatar
mattymax
Thread Starter
|
Fleet Mechanic
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Mar 2006
Posts: 1,519
Likes: 133
Originally Posted by fordman19762003
Honestly, I wouldn't want my emergency strobes wired into the key because then you have all the other acc. powered up too. My tandem dump trk has the beacon lights wired to the key and I have to manually turn off the radio, fan, etc.. so they don't run also. It would be nice to just shut the truck off and flip the switch to run the strobes.
No essentially I am changing the 7 pin from key on to constant power. Meaning my interior lights in the trailer will always work and I can wire a switch that comes on when my ramp door is OPEN only. So when I turn the truck off there is no drain. Until I open the ramp door. We're talking two small LED strobes The draw is next to nothing.
Matt
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-1

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-2

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-3

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-4

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-5

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-6

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
story-7

Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!

 Joe Kucinski
story-8

Every 2026 Ford Truck Engine RANKED from WORST to FIRST!

 Michael S. Palmer
story-9

The Best F-150 Deal of Every Trim Level (XL through Raptor)

 Joe Kucinski
Old Aug 14, 2017 | 04:46 AM
  #9  
Ferguson65's Avatar
Ferguson65
Logistics Pro
20 Year Member
Liked
Joined: Mar 2005
Posts: 2,536
Likes: 200
From: southeast PA
You can do this without rewiring anything. All you need to do is remove trailer battery charge relay and jump pins 30 and 87. Done. My truck was like that for 2 years, installed the jumper the day I drove it home new. Sold that trailer and now have the relay back in. Don't let anyone tell you it's a bad idea because Ford is the only brand that switches the trailer charge wire.
 
Reply
Old Aug 14, 2017 | 07:57 AM
  #10  
mattymax's Avatar
mattymax
Thread Starter
|
Fleet Mechanic
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Mar 2006
Posts: 1,519
Likes: 133
Any pics ?
 
Reply
Old Aug 14, 2017 | 07:41 PM
  #11  
Ferguson65's Avatar
Ferguson65
Logistics Pro
20 Year Member
Liked
Joined: Mar 2005
Posts: 2,536
Likes: 200
From: southeast PA
No pics. Don't know if the fuse box on a 13 and 08 would be the same anyway. If you can run a new fused wire you can locate and jump out a relay. The pinout should be labeled in its base.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bluefishgary
All Things Towing
5
Jan 21, 2012 02:49 PM
wezol5484
1999 - 2016 Super Duty
7
Apr 10, 2011 07:07 PM
78bigunns
Electrical Systems/Wiring
6
Apr 7, 2008 10:26 AM
Ding
1999 - 2016 Super Duty
20
Nov 6, 2005 07:18 PM
Ding
Electrical Systems/Wiring
2
Nov 2, 2005 08:52 PM




All times are GMT -5. The time now is 11:21 AM.

story-0
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-1
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-2
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-3
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-4
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-5
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-6
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE
story-7
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!

Slideshow: Ranking the 5 things owners love about their Super Duty and 5 things they don't

By Joe Kucinski | 2026-04-29 16:36:49


VIEW MORE
story-8
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!

Slideshow: Ranking all 12 Ford truck engines available in 2026.

By Michael S. Palmer | 2026-04-22 13:32:20


VIEW MORE
story-9
The Best F-150 Deal of Every Trim Level (XL through Raptor)

Slideshow: The best Ford F-150 deal for every trim level (XL through Raptor)

By Joe Kucinski | 2026-04-21 15:59:01


VIEW MORE