Power from 7 way to batteries

[arcticman1957]

Okay I have looked at all 17 pages and could not find a post on this subject. Several of us that travel around from job to job have been discussing this since the ice storm went through Northern GA.

Is there a way to run the center power pole of the 7 way to charge the batteries? Some of us went five days with no heat, except when we had jumper cables on the truck and the truck running.

Any help will be greatly appreciated.

Thanks, Jim

[atom ant]

I'm confused - Lug 4 on the plug is 12V battery charge power to the trailer.

At least on Ford, the key does have to be on for power to appear, probably a way to prevent inadvertently draining the truck battery if you parked for a while and were still hitched up. I'm not sure what GM does.

[rcflame]

The center terminal on a 7 way plug is an auxiliary terminal. Some use it for back up lights. If you wanted to do something different with the terminal, first you would have to see if this terminal is hooked up to something on your trailer. You could check the female receptical and see if there is a wire hooked to the center terminal and if there is trace it figure out where it goes. If it's not needed, you could run it to charge your batteries. You would than have to run a wire from your power source to the center terminal on your male plug on the truck. (you should fuse it ) Than you should have power from your power source to your trailer batteries, but like Adam says, you should already have a hookup to charge your batteries with the normal wiring. Your standard wiring for the 7way plug is this way. All p/us should be wired this way and I believe the truck has to be on for power to flow. I'm not sure what you're trying to do.

[atom ant]

In Ford (and Redwood), the center pin is backup lights. Not sure what the GM output is on the center, but the Redwood center lug will definitely turn on the backup lights if energized.

[mhs4771]

OK, enough Ford talk.

GM is the same, Center pin is the backup lights and is connected and works.
On some of the GMs you need to add the 40 amp fuse in the fuse block located in the engine compartment (if not sure which, send me a PM and I'll take a pic). Our 2011 was ordered with all the optional towing packages and came with the fuse installed and it provides Live 12V all the time, so when stopping for the night and not disconnecting I will pull the RW plug just to avoid the possibility of draining the TV batteries.
Now we just recently had a problem with that 12V and it turned out the Plug on the RW cord had that contact spread open, causing lose of 12V to the RW.

[arcticman1957]

one dodge with Montana, one ford with alpine and my GMC with RW and done of us could charge batteries just by plugging in and running truck. As stated earlier jumper cables was the only we could keep batteries up to run furnace.

[rcflame]

Was the battery in the campers down to start with. You could have been trying to do too much with the amps that was being provided by the vehicles. This is mainly to keep the batteries charged .

[mhs4771]

Don't know what to tell you. All I can say is that our 2005 and now our 2011 both provided 12V via the 7 pin connector to the trailer.
Did you get the towing package, including 5th wheel wiring on your Jimmy?? I can't state for sure if there is 12V at the bumper plug as I use a rcpt mounted in the bed which included the 12V line in the harness.

[atom ant]

Just put electric brakes on our boat trailer last weekend, and it needs trailer charge wire to charge a small break-away battery. Nothing from the wifes car's 7-wire socket out the back. Looked in the manual and found out there are spots for 30A charge wire fuse and a trailer charge relay all in the fuse box, none of which were installed at the factory. I had to go buy them Saturday at the Dealer. Charges great now.

Her car is a 2004 Fo.....er. SUV

[johnboytoo]

Guess my wiring on the previous 5er and must have been hooked up wrong then, because many a time I would hook up the 7 pin to dead batteries enough to raise the jacks and then be charged by the time we got to the campground...

just my results ....

[EWendlandt]

Our campground blew a transformer and we were able to run the 12v system off the truck plug until it was fixed. Approx 10 hrs or so. We were using the furnace at that time as well.

[rcflame]

Arcticman,
Have you checked the trucks to make sure you have power to the center plug of the receptacle . I think I would start there and if I didn't have power start checking the truck.

[arcticman1957]

Originally Posted by rcflame

Was the battery in the campers down to start with. You could have been trying to do too much with the amps that was being provided by the vehicles. This is mainly to keep the batteries charged .

RC, this kind of the conclusion we came to that it must like a tickle charger.

[TNTBaker]

Originally Posted by arcticman1957

RC, this kind of the conclusion we came to that it must like a tickle charger.

Well WHO DOESNT?!

[Botkind]

My truck charges battery going down the highway but the battery disconnect has to be on. Won't charge batteries if they are disconnected.

[Rick and Mindy]

Originally Posted by Botkind

My truck charges battery going down the highway but the battery disconnect has to be on. Won't charge batteries if they are disconnected.

You need to always have the battery switch on when you are going down the road or your emergency brake switch will not work if needed.