7 Pin Wiring for Trailer

[Jimmy Lavoie]

I recently upgraded my trailer's existing crank tongue jack to an electric tongue jack.



During that upgrade, it was determined that one of the electrical connections was not working - the one that is supposed to power the trailer refrigerator while towing. In the past, when we towed the pop-up to go camping, we'd turn the fridge to battery (12v) so it would start getting cold while we were going to our destination. Worked fine - for a while. We've recently noticed that the refrigerator is NOT cold anymore.



Apparently, it's the same plug that is supposed to charge the battery for the electric tongue jack - also while towing.



The RV place that added the battery and the electric jack said that it was a fuse in the fuse box that controlled that.



With that back history, does anyone know which fuse controls that? It's an 07 with the fuse box under the hood.

 

[Tom Schindler]

Read your owners manual. That will tell you exactly what fuses are what.





Tom

 

[Jimmy Lavoie]

That's the rub... can't find it. I'll keep looking - Thanks Tom.

 

[Gavin Allan]

Download a new manual for free from the Ford Owner Website:

 

[Tom Schindler]

Click the link below...





Tom

 

[Jimmy Lavoie]

Thanks guys

 

[Jimmy Lavoie]

I'm not electrically savvy so I have a few more questions:



There are two fuse box areas shown in the document

1. Under the left side of the steering wheel (just above your left knee as you drive)

2. One in the engine compartment - Power Distribution Box (PDB)



The one inside says theres a 5A fuse in slot 12 described as: "RUN accessory - Radio, Tailer tow battery charge (relay in PDB)"



In the PDB, slot 13 - 30A fuse, describes: "Trailer tow battery charge" AND slot 54 describes: "Trailer tow battery charge relay".



I guess?... I should first take a look to see if the 2 fuses in slots 12 (inside) and slot 13 (PDB) are good. If they are - then - is there a way to check the relay in slot 54 (PDB)?



I'm at work now but I'll give a look tonight when I get home and report my results tomorrow.

 

[Aaron Yarbough]

I bet it's the fuse under the left side of the steering wheel. Have experienced something similar with mine and it has always been the fuse box under the dash. I doubt the relay is the problem...

 

[Jimmy Lavoie]

Well, I checked all the fuses and everything's good. Nothing is burned.



My next question is - how can I check the 7 pin connector at the tailgate to see if it's getting power to the correct pin to charge the battery on the trailer while driving?



Is there a chart that describes what each of the 7 copper connectors (pins) are supposed to power?



I had the 7 pin connector installed by a local shop 3 years ago and I want to make sure they connected all the wires properly.

 

[Les]

Jimmy, Steve M is usually the one posting this type of information...

 

[Jimmy Lavoie]

I found a diagram showing the 7 pins and what they are supposed to power.



I assume that if the pin that is for the battery charge is wired, it should be hot when I test it. I'll give it a try.