I've bought a travel trailer and just now found out the relay for the Trailer Tow battery charger is not installed in the power distribution box. In case you don't want to read the "story", I am looking for the part number or a picture of the relay installed. I am under the assumption putting the relay in, along with the 30 amp fuse in position 21, and my truck will charge my travel trailer battery while driving down the road.

Actions I've taken to try and find out what this part number:

According to the owners manual it goes in Fuse or Relay #9. It does not give the Fuse amp rating, that column is just blank, the description is "Trailer Tow Battery Charger Relay"
I did not get a plastic bag with the relay and fuse in my truck but it does have the factory installed tow package
I've contacted two dealerships, including the one I bought it at, and they have no idea what the part number is
Googled the hell out of it. I found lots of sites talking about the "missing" relay but no one listed a part number or photo of it
I've gone to two auto parts stores, O'reilys and Autozone, and neither had a clue what relay I need because it would not come up in their computers

I just need to know what relay to put there and thanks in advance for your assistance.

 

For the little plastic bag that has the relay and fuse the part number is AL3T-15A416-AA
For the relay alone the part number is 8T2Z-14N089-D and goes into Relay #9 in the power distribution box
For the fuse alone the part number is 6E5Z-14526-BA and goes into fuse #21 in the power distribution box

 

I have never had it charge my dump trailer sufficiently. Having said that, I don't take very long trips either.

 

The packet that came with my 2013 STX lists slightly different part #'s:

Baggie with relay, fuse and adapter for electronic brakes 9L3T-15A416-AC containing:

Relay alone 8L8T-14B192-AA, position #9,
Fuse alone 6E5T-14A094-BA, position #21,
Brake adapter alone 9L3T-14A348-AC, connected under dash.

Have no idea why mine has the adapter and pahealy doesn't unless he simply didn't list it or his truck isn't set up with the 7 pin trailer plug or ???.