battery charging
Many years ago my wife and I purchased a 18 foot Road Runner tt. If I remember right the batteries charged when plugged into the truck and driving down the road. Now nearly 40 years later we purrchase...
Forum Discussion
One way to check is plug in your trailer cable to your truck and use a multimeter across the trailer battery terminals which should read around 12.5-6VDC if fully charged up.
Then go start up your truck motor and read the trailer battery terminals again with the multimeter. It should now be reading an increase in DC voltage depending what charge state your truck alternator is doing. It should read between 13.2VDC to 14VDC or so... If it reads the same as when you read it before the truck is not connected to your trailer 12VDC wiring.
Maybe you have a trailer battery disconnect switch in the OFF position.
Another issue I had was my 2010 FORD TRUCK TOW CHARGE was not activated until I plugged in a fuse and a relay in the truck fuse panel. It was called TRAILER TOW (I think) in my truck manuals. This only gives me TRAILER TOW VOLTAGE when the truck ignition key is turned ON.
Roy Ken
Then go start up your truck motor and read the trailer battery terminals again with the multimeter. It should now be reading an increase in DC voltage depending what charge state your truck alternator is doing. It should read between 13.2VDC to 14VDC or so... If it reads the same as when you read it before the truck is not connected to your trailer 12VDC wiring.
Maybe you have a trailer battery disconnect switch in the OFF position.
Another issue I had was my 2010 FORD TRUCK TOW CHARGE was not activated until I plugged in a fuse and a relay in the truck fuse panel. It was called TRAILER TOW (I think) in my truck manuals. This only gives me TRAILER TOW VOLTAGE when the truck ignition key is turned ON.
Roy Ken
