7 Pin Trailer Plug [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: 7 Pin Trailer Plug


Lakedaisy
11-24-2003, 10:40 PM
Will the truck charge the batteries in a 5th wheeler through the trucks trailer plug? Thanks.

RMAX
11-24-2003, 10:45 PM
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

Dmax Tim
11-25-2003, 06:13 AM
Yes u have battery power thru the plug but u can also drain the truck batteries if u don't pull the plug when parked.


I've got a truck camper and leave them plugged in all the time but only stop for the night, so I'm drawing from 3 batteries.


The 40 amp fuse u put in under hood powers this wire so it should charge pretty good.


An isolator or low voltage disconnect could help so u don't drain the truck.

Lakedaisy
11-25-2003, 11:06 AM
Thanks.


Dmax Tim, whats an isolator or low voltage disconnect?

mfendley
11-25-2003, 11:16 AM
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.

Lakedaisy
11-25-2003, 11:51 AM
OK. Thanks mfendley.

edzzed
02-15-2004, 09:45 PM
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

army
02-15-2004, 09:52 PM
http://www.dieselplace.com/forum/smileys/Clown.gifI just uplug my trailer plug when I'm parked. No big deal.

Zeeb
02-15-2004, 10:59 PM
I thought the new trucks came with a low voltage cut out relay?


Going to have to dig into that Owner's Manual again....http://www.dieselplace.com/forum/smileys/Ermm.gif


edit info:


Okay, looked in the manual, what I saw was a reference to the low battery cut off for the dome and cargo lamps.....http://www.dieselplace.com/forum/smileys/Confused.gif


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