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trailer plug wiring

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Old Aug 15, 2010 | 04:36 PM
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trailer plug wiring

i have a 1996 f 150 2x4. i am trying to wire up a 7 prong plug in the back. i have the plug underneath the dash for the brake controller but i need to wire up the plug in the back. there is a 4 prong currently back there that just plugs into a harness. is there a plug in for the 7 prong plug?
 
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Old Aug 16, 2010 | 02:31 AM
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Do you have a brake controller?

Your truck is a 4x2 by the way not a 2x4. LOL...
 
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Old Aug 16, 2010 | 06:51 AM
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From: Easton,Ks
Originally Posted by 2000f-1507700
i have a 1996 f 150 2x4. i am trying to wire up a 7 prong plug in the back. i have the plug underneath the dash for the brake controller but i need to wire up the plug in the back. there is a 4 prong currently back there that just plugs into a harness. is there a plug in for the 7 prong plug?
If you do not have the towing package then no there is not and the BLUE wire for the breaks stops at the safety wall.

If you have the towing package the you will have the small relay box beside the big fuse relay box and wires plugged into the two plugs (C149 & C105) on the drivers inter fender.


Wiring with and without the tow package.


/
 
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Old Aug 16, 2010 | 07:44 AM
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Subford, do you know what's the logic behind having a relay for the trailer backup lights, but not the running lights? Is it because they planned on the customers using 55W flood lights as backups on the trailer? Cause a large trailer with lots of running lights can make for quite the current draw too, granted it probably won't be no 10 amps but it's an extra load on the main lights switch and we all know how good those are at handling additional loads...
 
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Old Aug 16, 2010 | 07:58 AM
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I've been wanting to get the factory setup like Subford just mentioned off of a salvage yard truck.

Originally Posted by LCAM-01XA
Subford, do you know what's the logic behind having a relay for the trailer backup lights, but not the running lights? Is it because they planned on the customers using 55W flood lights as backups on the trailer? Cause a large trailer with lots of running lights can make for quite the current draw too, granted it probably won't be no 10 amps but it's an extra load on the main lights switch and we all know how good those are at handling additional loads...
Your right about that. Thats why I got the headlight relay harness like the one LMC sells, so that the switch didn't carry the load of the lights. It also made the lights a little brighter. Thats also part of the reason that I don't know if having the 3 running lights under the tailgate is a good idea or not. I like how they look but can't decide, so sometimes they are on the truck and sometimes they aren't. They are tied into the license plate lights. I was thinking about putting a weatherproof switch back there, so I can turn them off when hooked up to a trailer. That would put less load on the switch and electrical system.
 
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Old Aug 16, 2010 | 07:58 AM
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From: Easton,Ks
But they do have one for the running lights for the trailer and it does not put any more load on the main light switch.
It is called the trailer marker lamp relay.




/
 
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Old Aug 16, 2010 | 12:22 PM
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Originally Posted by TexasGuy001
Your right about that. Thats why I got the headlight relay harness like the one LMC sells, so that the switch didn't carry the load of the lights. It also made the lights a little brighter. Thats also part of the reason that I don't know if having the 3 running lights under the tailgate is a good idea or not. I like how they look but can't decide, so sometimes they are on the truck and sometimes they aren't. They are tied into the license plate lights. I was thinking about putting a weatherproof switch back there, so I can turn them off when hooked up to a trailer. That would put less load on the switch and electrical system.
Relay the running lights as well, it's a simple mod and takes care of all kids of issues. This is also part of the factory towing package, that I'm lucky enough to have, but being an older truck I don't get the battery charge and backup lights relays, those must be a '92-'96 thing.

Originally Posted by subford
But they do have one for the running lights for the trailer and it does not put any more load on the main light switch.
It is called the trailer marker lamp relay.
Oh, okay, it's in the main power distribution panel the, not in the one for the towing package - that's what threw me off. Thanks for the diagram and pictures.
 
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Old Aug 16, 2010 | 01:54 PM
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Thats true, a relay would work for that too. I don't currently have the trailer wiring for the tow package. All I have is the 4 pin T adapter. I thought my truck had towing package but I guess it didn't.
 
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Old Aug 16, 2010 | 03:20 PM
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Use Subford's diagram above and make yourself a trailer package It really ain't hard, minorly annoying maybe, but not hard - grab a case of beer and call it a Saturday's project...
 
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Old Sep 20, 2010 | 10:12 AM
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Im in the same boat I have a hitch, a 7 pin connector, a brake controler, and the under dash connector. However, I get no brake response from the trailer just blinker and brake lights (I taped into the stock rear end wireing). The diagram looks mighty intimidating, is there a DIY guide somewhere? Or a at least the parts needed for this project?
Thanks!
 
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Old Sep 20, 2010 | 10:18 AM
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From: Easton,Ks
The diagram is of the stock wiring of the F-series 92-95 with the towing package, it is not a project.
 
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Old Sep 20, 2010 | 10:32 AM
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Im guessing I don't have the stock tow package wiring.Although there is a plug under the dash. I would like to get everything working though. That's why i was asking fora DIY guide, parts list, or something to help me get started.
Thanks!
 
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Old Sep 20, 2010 | 10:45 AM
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From: Easton,Ks
I did not have the towing package on my truck either.
What I did was I went to a salvage yard and removed the two relay box and the wiring harness that runs from the safety wall to the rear bumper off a like truck with a towing package.
Then I put the items on mine.
It was just plug and play, no DIY guide needed.
 
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Old Sep 20, 2010 | 10:59 AM
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Originally Posted by subford
I did not have the towing package on my truck either.
What I did was I went to a salvage yard and removed the two relay box and the wiring harness that runs from the safety wall to the rear bumper off a like truck with a towing package.
Then I put the items on mine.
It was just plug and play, no DIY guide needed.
Great suggestion, I'm going to the salvage yard today and see if I can find the two relays and the wire harness!
 
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Old Sep 20, 2010 | 01:40 PM
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OK so i have a question while we are on wiring acc stuff... I just put a aftermarket 6 (or 8 can't remember) fuse block under the hood to run my accessories... Looks like this

10 POSITION AUTOMOTIVE FUSE BLOCK: eBay Motors (item 230395707146 end time Sep-30-10 11:56:20 PDT)

I am running a 10 gage line to it so i can run bigger things through it... I have the following accesories wired into it but don't know what fuse to use on them... Anyone think i need to change the following...

air horn - 20 amp fuse
acc wire to 7 pin - 30 amp fuse
electric trailer break power wire - 30 amp fuse
halogen fog lights - 25 amp fuse

Also before anyone states the obvious I have alread swaped my 2g for a 130amp 3g alternator... I don't have any of the origional packaging for the acc items so i was just guessing on their draw and fuse size... let me know if you guys think in need to make a fuse smaller or bigger. Thanks!
 
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