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Trailer backup light relay
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Trailer backup light relay
I have a 2000 SD V10 4x4. I recently bought a new bass boat and the trailer has backup lights. I can do without the lights however the trailer brakes require the backup light feed to release in order to back up. I pulled the boat home, but can't back it down the boat ramp because once the trailer starts rolling backwards without the backup light feed the brakes lock. Obviously this is not good. I have located the box that would house the trailer backup light relay and the trailer battery charge relay. Which plug is which, and what size relays and where do I get them?
Thanks,
John
Thanks,
John
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New User
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Yeah. Theres 3, one big and its the power distribution box and 2 smaller ones. One is for the shift on the fly and the other houses the trailer backup light relay and the trailer battery charge relay. Thanks for the welcome.
John
John
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From: SW ND
www.motorcraftservice.com You can click on Owner Guides to find the appropriate guide. It shows it Slot number 38 for Backup relay and 39 for Charge relay. Might only be the only 2 slots that have contacts in them, some are empty w/o contacts
You can get the relay's at your Ford dealer, might be spendy but worth it for quality relay's.
You can get the relay's at your Ford dealer, might be spendy but worth it for quality relay's.
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Joined: Jan 2007
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From: Houston, TX
Are you using the 7-pin trailer plug? If so, the center pin is the AUX feed and it goes hot when you backup. For my auxillary backup lights on my truck, that's where it indicates to tap in to. I also tapped into that pin for the the backup camera and the backup lights mounted on back of the travel trailer.
rgds,
TX
rgds,
TX
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Figured it out. There are two smaller boxes beside the fuse box under the hood. One runs side to side and it has the shift-on-the-fly relays. The one running forward and aft houses the trailer battery charge relay and the trailer backup light relay. The trailer backup light relay is the one closest to the firewall. The relay required is Ford part number is FOAZ-14N089-A, they are about 10 dollars from the ford store. Any parts store should be able to cross reference the ford number and come up with one for about 2 dollars less. The NAPA number is AR659.
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From: Houston, TX
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Yes I did, but the relays for the trailer battery charger and trailer backup lights are not installed from the factory. They normally come in a bag in the glove box. I bought the truck used in 02 and they were not in there. Never needed them and thus didn't know anything about them.
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From: Houston, TX
Wow, now I'm really curious to get home and look at mine.
My travel trailer charges via the 7-pin harness, and although the tt doesn't have backup lights, my auxillary backup light wiring guide had me tap the center pin (AUX) on the 7-pin harness, which goes hot when in reverse.
So I'm guessing those relays are already installed. I bought the truck used as you did, so not sure.
Good info, thanks!
TX
My travel trailer charges via the 7-pin harness, and although the tt doesn't have backup lights, my auxillary backup light wiring guide had me tap the center pin (AUX) on the 7-pin harness, which goes hot when in reverse.
So I'm guessing those relays are already installed. I bought the truck used as you did, so not sure.
Good info, thanks!
TX
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Joined: Jul 2006
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Alot of boat trailers have the 5 pin connector (same as 4 pin with the extra bottom pin). the bottom pin activates the reverse lights and can lock out a solenoid on surge hydraulic brakes, which most boat trailers have, to bypass the surge brakes.
My SD has a four pin and a 7 round on the hitch. There are adapters for 5 pin to 7 round. I simply plug the boat trailer 5 pin into the 4 pin. When I need to reverse, you have to flip the trailer plug upside down and turn on your lights, that will give power to the reverse pin and your lights and lockout will work. Somewhat of a pain and I forget now and again and the trailer brakes lock up when reversing.
I will probably end up replacing the 4 pin with a 5 pin and either tapping the AUX on the 7 round or the reverse light hot to power the fifth pin. A 4 pin will work in a 5 pin.
My SD has a four pin and a 7 round on the hitch. There are adapters for 5 pin to 7 round. I simply plug the boat trailer 5 pin into the 4 pin. When I need to reverse, you have to flip the trailer plug upside down and turn on your lights, that will give power to the reverse pin and your lights and lockout will work. Somewhat of a pain and I forget now and again and the trailer brakes lock up when reversing.
I will probably end up replacing the 4 pin with a 5 pin and either tapping the AUX on the 7 round or the reverse light hot to power the fifth pin. A 4 pin will work in a 5 pin.
Lead Driver
Joined: Sep 2003
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From: Albuquerque
Originally Posted by atcje
Figured it out. There are two smaller boxes beside the fuse box under the hood. One runs side to side and it has the shift-on-the-fly relays. The one running forward and aft houses the trailer battery charge relay and the trailer backup light relay. The trailer backup light relay is the one closest to the firewall. The relay required is Ford part number is FOAZ-14N089-A, they are about 10 dollars from the ford store. Any parts store should be able to cross reference the ford number and come up with one for about 2 dollars less. The NAPA number is AR659.
OBTW: Now I am going to check my SD. I purchased it Used...and the previous Owner removed the OEM 7/4 pin that comes with the tow package and installed a 6 pin (hack job).
Just finished removing the 6 pin...and installed a NEW OEM 7/4 pin. FORD Part #2C3Z13A576DA (Thanks Ed from y2kford parts). I like OEM when possible!
Now off to see about the trailer battery charge relay and the trailer backup light relay.
biz
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Joined: Jan 2005
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From: Peoria, IL
We had a discussion about this a week or so ago. I guess that only the 99 and 00 trucks have to have the relays added, the newer trucks come with everything in place from the factory.
Flux, I would think it would be easier to upgrade your boat trailer to a seven pin connector rather than messing with your truck wiring.
Flux, I would think it would be easier to upgrade your boat trailer to a seven pin connector rather than messing with your truck wiring.
Lead Driver
Joined: Sep 2003
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From: Albuquerque
Originally Posted by Beerstalker
We had a discussion about this a week or so ago. I guess that only the 99 and 00 trucks have to have the relays added, the newer trucks come with everything in place from the factory.
I guess I can rest easy then...
biz
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Originally Posted by Beerstalker
We had a discussion about this a week or so ago. I guess that only the 99 and 00 trucks have to have the relays added, the newer trucks come with everything in place from the factory.
Flux, I would think it would be easier to upgrade your boat trailer to a seven pin connector rather than messing with your truck wiring.
Flux, I would think it would be easier to upgrade your boat trailer to a seven pin connector rather than messing with your truck wiring.
Beerstalker, you are very wise. I may do just that as my buddy hauls it too and he has an F150 with the same plug setup but no controller.
I would buy you a beer for that nugget of info, but internet does not let me.
thanks.