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Lickitysplit
11-19-2007, 11:44 PM
I'm trying to get my final preparations in order on my tow vehicle as our new 3400RL is supposed to roll of of the line Tommorrow (11-20-07). I will be picking it up at the Dealer the first week of Dec.

I am going to add a trailer plug in the bed of my truck and have been told to run a separate 8 guage wire from the battery of the TV to the plug on the 7 pin trailer connector. The larger wire is supposed to charge the (coach) batteries faster and carry more current (less voltage drop). I have seen a post on this forum with all of the details but I can't seem to find it now and I was going to try to get-er done tommorrow while the weather is still nice.

I think if I remember right, on my GMC truck, you can run the 8 guage wire from the junction box under the hood (red) where the alternator charge wire connects to the battery cables going out to each separate battery. Also, I think it is recommended to install a 50 amp self resetting circuit breaker in this line.

I took the female trailer plug apart today and looked at the screw terminals on the plug and was wondering if a 8 guage wire will fit in there?? I am sure I will have to use some sort of connector on the end of the wire.

If anyone has any advice or can send me a link to the proper thread I would appreciate it.

Also, does anyone know what size wire Heartland uses from the trailer plug on the RV to the (coach) batteries. I think I recall seeing somewhere that they use 10 guage wire. And if it is 10 guage shouldn't it be 8 guage like on the TV ??

Any help would be appreciated as always.
Thanks, Jeff :)

v92c
11-20-2007, 12:21 AM
I think I would solder a smaller piece of wire, that will fit into the screw terminal, to the end on the 8 gauge wire. And then cover it with heat shrink or electrical tape. A piece of solid copper wire, maybe 12 gauge should work nice. If you make the jumper wire short, like 1/2 inch it should get too hot and handle the current.

Tony

katkens
11-20-2007, 07:27 AM
Jeff, you should have a harness with all the wiring you need already. If you look on top of the frame behind the driver side there is a harness coiled up. The harness is long enough to snake to the rear of the bed ,where I mounted mine. If you got a factory brake control harness with the truck there is a square fuse taped to it that has to be installed in the fuse box under the hood for the charging circuit to work. Its not necessary to run any extra wires on the GM's to make the charging work . I hope this helps and if not keep asking away or PM me....Ken

Lickitysplit
11-20-2007, 10:47 AM
Katkens, I took the truck down to the dealer and we looked under it everywhere and could not find a factory harness. They said the truck has to be ordered with the camper special option (for use w/slide camper) for it to have this additional harness. Of course my truck has the factory installed trailer plug on the bumper. I am just going to slice into that harness and extend the wiring up into the side of the bed. It looks to me like the 12 volt line that supplies power to the coach is 10 guage? Is this 10 guage big enough?? Or do I need to run the separate 8 guage wire as advised??
Jeff

katkens
11-20-2007, 11:02 AM
Katkens, I took the truck down to the dealer and we looked under it everywhere and could not find a factory harness. They said the truck has to be ordered with the camper special option (for use w/slide camper) for it to have this additional harness. Of course my truck has the factory installed trailer plug on the bumper. I am just going to slice into that harness and extend the wiring up into the side of the bed. It looks to me like the 12 volt line that supplies power to the coach is 10 guage? Is this 10 guage big enough?? Or do I need to run the separate 8 guage wire as advised??
Jeff

If I was a betting man I'd bet that harness is there, mine does not have the camper special option. It should come with the towing package ,hd trans cooler ,hitch etc. The 10 ga. wire would be sufficient but with wiring bigger is always better but the gain here is not that much.

Uncle Rog
11-20-2007, 01:37 PM
Make sure the fuse is installed for the charging system, it comes with the wiring harness unit. On my 05 it was not pre-installed and it will not charge if it is not....guess how I know.........

Lickitysplit
11-20-2007, 09:14 PM
Katkens, I am going to put it up on a lift and double check to see if I can find the harness but I have been under it thoroughly on a creeper and unless it is above the fuel tank (which you can't get to) my truck doesn't have the additional harness. My truck does however have the heavy duty trailer package, heavy duty trans cooler, hitch, etc.

So I guess you think the 10 guage wire for 12 volt line to the coach thats in the factory harness is adequate to charge the coach batteries??

Uncle Rog, Thanks, my 40 amp fuse for the charge line is installed.


Thanks,Jeff

katkens
11-21-2007, 10:26 AM
Katkens, I am going to put it up on a lift and double check to see if I can find the harness but I have been under it thoroughly on a creeper and unless it is above the fuel tank (which you can't get to) my truck doesn't have the additional harness. My truck does however have the heavy duty trailer package, heavy duty trans cooler, hitch, etc.

So I guess you think the 10 guage wire for 12 volt line to the coach thats in the factory harness is adequate to charge the coach batteries??

Uncle Rog, Thanks, my 40 amp fuse for the charge line is installed.


Thanks,Jeff

The 10 ga. will work just fine. The harness on mine was about a foot back from the bed on top of the frame, it was crammed under the light harness, etc. going to the rear. It was kinda hard to get it pulled out of there. Its the typical taped up looking harness.....Ken

P.S Forrest has an '06 GMC and his harness was coiled near the rubber fill hose at the fuel tank.