RV battery drains while towing: Ford 150 fix?

[Steve-o]

Presume that there is nothing abnormal about the RV connections. The 7way socket on the truck was checked with a voltage meter. I don’t remember the output voltage with the truck on but when i checked it it was within specs. But the RV battery drains more than it recharges while towing. The refrigerator is not on electric (it doesn't run on 12v anyway). and all the interior lights are out.

I recall reading in some blog or forum that for a Ford F150 there is a fuse you can add to the truck fusebox that would increase the alternator output to cover the TT drain and charge the battery while towing.

Does anyone know more about this, like adding a fuse to an empty slot, or another add on, will increase the alternator output under towing conditions? Thanks in advance

[NH_Bulldog]

First question is; has it ever worked?

Second, the only way to test the output with your F150 is with the trailer connected, and the truck running (it might even have to be in gear, I don’t recall). This is to prevent the trailer from draining the truck battery.

When I had my F150 it had the max tow package and there was nothing to set up, it just worked (and it worked very well). You cannot “boost” power output to the trailer because the auxiliary power wire in the truck and to the 7-pin plug is pretty small, and only permits a limited amount of amperage. That being said, if it was working at all, you would not only not drain the trailer batteries, but actually charge them while driving down the road.

I have heard of an empty slot in the under hood power center that doesn’t always come equipped with a fuse and if that is the case, it is an easy fix. Like I said, mine had it so I can’t tell you which one it is, and I don’t have that truck any longer. But you can google it and find plenty of links to guide you.

[flybouy]

Unfortunately you didn't share some information that would help you get some accurate ideas. There's no telling what year your truck is or the year and model of your trailer. For years Ford F150 came from the factory with a fuse in a zip lock bag with instructions on the socket location with instructions to insert it to allow charging the trailer battery.

[curtiscapk]

Here you go!

https://www.keystoneforums.com/forum...5&postcount=11