On my 93 chevy the 5th wheel battery would charge if driving all day. The charge rate is pretty low so if you start with a low battery it's going to take a while. Have a new 04 but I'm assuming it'll be about the same
An isolator will allow the truck alternator to charge the trailer batteries, but the trailer can't discharge the truck battery when the truck isn't running. The low voltage disconnect allows the truck's battery to be used down to a certain voltage, and then the truck battery is isolated from the trailer, leaving enough voltage in the battery to start the truck.
i'd say put a relay on the charge line to the trailer and wire it in so it only supplies power while the engine is running, will not drain trucks battery this way because it disconnects from the system when the engine does not run. a good wire to power the relay is from the wiper motor or daytime running lights
I thought the new trucks came with a low voltage cut out relay?
Going to have to dig into that Owner's Manual again....
Okay, looked in the manual, what I saw was a reference to the low battery cut off for the dome and cargo lamps.....
You'll need that isolator if you want to keep the trailer plugged in while parked, but I like the idea of just unplugging it. Your Dmax has two batteries for a reason and if you drain them much with the trailer, or in my case a camper, it ain't gona start....Edited by: Zeeb
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