TT battery charging question?

A pic is worth a thousand words ... ;)

It depends.... Most newer trucks provide the TRAILER TOW FUSE and RELAY in a plastic zip bag laying in the glove box which need to be installed in the main fuse panel first. You will have to check your service manual and find the slots where the FUSE and RELAY goes. I think mine was marked TRAILER TOW or something like that in the diagram pictorial of the fuse panel that is mounted on top of the radiator in my 2010 F150 truck.

This allows the BATTERY in the trailer to be charged from the truck side when you plug in the 7-way trailer cable in when the truck ignition key is turned ON...

You can test this by using a MULTIMETER across the battery terminals which will read 12.6-7VDC if the trailer battery is fully charged. After hooking up the 7-way CABLE and starting your truck you should see the DC VOLTAGE across the battery terminals jump up to 13.6VDC or more depending what the truck alternator system charge mode is in.

You will not get much charging coming from the truck setup however. The distance from the alternator and the size of the charge wire limits the battery charge alot. You may only get around 6 amps or so of charge current so it really just be thought of a good top-off charge for your trailer battery as your drive down the roads. You can still run down the trailer battery if you exceed the charge current coming from the truck alternator system.

This is what I had to do for my 2010 Ford truck setup. Your truck may be different so just do the TEST first to see if it proving a charge DC VOLTAGE at the trailer battery when your truck is running.

Roy Ken