Battery not charging while hooked up to truck

[boulderado]

We recently traded TVs from a Yukon Denali to a newer F-150 and on our outings so far I've noticed that the truck does not seem to charge the battery. It powers the lights and brakes just fine, but it seems to have no impact on the battery. In the past when the trailer had been in storage for a week or so, the battery would be nearly dead, but as soon as the Denali was hooked up the tongue jack ran like a champ, with the F-150 not so much. I am definitely due for a new battery, but thought I would see if you have any input into why this is happening. Thanks.

[tvman44]

There is a fuse and a relay in the charging circuit of Fords, on or the other could be bad. 🙂
PS on Fords the ignition switch has to be in the run position for the relay to pull in for charging. 🙂

[dockmasterdave]

My new 2014 f 150 came with the baggie in the door pocket.
On my older ones, I just had to look in the owners manual, and see where the "trailer charge" fuse and relay went. There should be one of each.

[boulderado]

Thanks, guys, I knew you would have the answer. I will look for the fuse after work today.

[Old-Biscuit]

In the engine compartment is the power control center (main fuse/relay panel)

On the inside of lid is the various fuse/relay positions.

#17 30A Trailer Brake Control
#21 30A Trailer Battery Charge Relay....usually not installed. Also check that wire has been attached
#43 15A Trailer Backup Lamp Relay
#67 20A Trailer Park Lamps Relay
#73 20A Trailer Stop/Turn Lamp Relay

[mbopp]

Yup, look for a plastic bag with a relay, fuse, and instructions. The F150 charge line is hot with the key on. GM's are hot all the time.

[iseesam]

Check your glove box for a relay and/or fuse that will enable the 12v charging pin on your connector. I do not believe that the fuse and/or relay come installed from the factory. Check your owners manual for more information on this.