f 150 charging pin warning

[Scotccrn]

I posted this on RV.net too but I want everyone to know to avoid costly repair.
For all you F-150 owners, found out today that my battery charging pin in my 7pin plug was dead. Therefore, it has not been charging or providing power to the trailer for the year that I have owned the trailer. I was about to take it to the dealer when I did an internet search. Apparently, Ford does doesn't like to have that pin hot from the factory. If you look in the baggie that came with the truck, you will find a relay plug in the bag with the brake controller harness. This needs to be installed in order for the battery charging pin to be hot. This may have been covered already in previous posts but I did not see it. The truck or trailer did not inform me of this. The diagram and instructions to install it are in the bag. This saved me $100 or more. You might want to check your pin/fuse panel. You might be going without battery charge too.

[f6bits]

I wouldn't classify it as a "repair." I posted my runaround a while back. After getting my truck, I discovered my trailer wasn't getting power, which bothered me because I was expecting it to charge while I was on the road.

I added the baggie parts, and it *still* didn't charge. It turned out that the fuse relay thingie on my trailer was blown and wasn't passing power from my trailer plug to the battery.

[richf28]

I found out mine wasn't hot when I stopped overnight at a Walmart in January on the way to Florida. The furnace wouldn't come on because the battery was dead. So wife and i cuddled up in hoodies jogging pants and bunch of blankets because it was 30 degrees out. After settling in at the resort the next day I inquired at the local rv dealer and they told me about the little bag. I knew it was in the glove box but always thought they were spares. There was no instructions. Looking in owners manual I found the location to install them and like magic it worked. We learn everyday.

[LiteFoot]

My 2010 Chevy was the same way. The power wires that sent power to the brake controller and the 7-pin were zip tied to separate wiring harnesses. I had to cut them loose and then put them on the correct post. Not a huge pain, but a little unnecessary on Chevy's part.

Ryan

[Jables]

My f150 charges fine. One day I decided to keep the truck running and plugged to the trailer while I opened the slide. It killed my gas gauge temporarily.

[ftwildernessguy]

I have owned my f150 for 8 years and never knew that baggie existed. I know that I couldn't charge the battery with the truck last year when we were living in the trailer after the hurricane, so I kept pulling the battery and taking it in to my office to charge. Read this thread today and went out to the truck to look. Sure enough, there it was. Didnt need the wiring since I had the brake control installed at the RV dealer. Guess they never checked for power to the battery. So I read the instructions and 2 minutes later, we are good to go. Many thanks to Scotccrn.

[Tri Tip]

Yep I had to order the relay from ford $40. You can test your battery tow charge from the truck by pluggin in your 7 pin then disconnectiong your TT batteries. If you interior TT lights come on your charging!

[ftwildernessguy]

Yep I had to order the relay from ford $40. You can test your battery tow charge from the truck by pluggin in your 7 pin then disconnectiong your TT batteries. If you interior TT lights come on your charging!

The truck needs to be running for this to work.

[LittleJoe]

Just put a volt meter across trailer battery when plugged into tow veh and engine running. It should read charging voltage 13.5-14.5 if it is getting power from truck lead

[Tri Tip]

The truck needs to be running for this to work.

Thanks forgot that part. Ford doesn't leave the wire hot while the ignition is off/parked. This way when you camp at wal-mart you wont wake up to a dead truck battery. :(

[eartha]

Thanks for the post on the relay. Just bought a new 150 and did not know what the spare parts was for. I thought they just give me an extra. No instructions but looked in manual and found where it went. I just thought it was charging. Thanks again."bouncey:

[dschamp]

Thanks for the heads-up. Would have assumed it was charging until I had a problem...likely at the worst possible time! (tx)

[Aulby]

Thanks for the heads up.

I have a 2012 F 150 and I pick up my 31bhpr on Saturday.

I found the relay and fuse in the glove box.

I appreciate the postings for a newbie like me.

Gg'em

Aulby '94

[RaptyJon]

Good to know - I'll have to check this out as well.

[Mark TC]

I checked mine last Thursday, the fuse and relay were in the manuals for the truck. I installed them


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[RaptyJon]

Can anyone take pictures of the necessary modifications being talked about here? The only bag in my glove box is for the rear view camera wire protector or something. I'm guessing/hoping that this has already been taken care of on my truck as I don't have my trailer to pull the batteries and give it a live a test at the moment.

[eartha]

Can anyone take pictures of the necessary modifications being talked about here? The only bag in my glove box is for the rear view camera wire protector or something. I'm guessing/hoping that this has already been taken care of on my truck as I don't have my trailer to pull the batteries and give it a live a test at the moment.
If you look in the owners manual it will show you the slot for the relay. All you need to do is look, it may already be installed. It is # 9. Page 299 in the book.

[Terrydactile]

The large square 30A relay goes in position #9 (trailer tow battery charger relay) and the cartridge type 30A fuse goes in position #21 (Trailer tow battery charge relay power). If these slots are filled then you should be good to go. If not simply plug the relay and fuse in.

[RaptyJon]

The large square 30A relay goes in position #9 (trailer tow battery charger relay) and the cartridge type 30A fuse goes in position #21 (Trailer tow battery charge relay power). If these slots are filled then you should be good to go. If not simply plug the relay and fuse in.


I have fuses in both #9 and #21 locations so I should be good.

Thanks all!

Jon