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egarant's avatar
egarant
Nomad
Oct 07, 2013

Battery Isolator

Hi,

My new 2013 RAM 3500 HD CC LB Diesel Dually was factory wired with the 5th wheel package, which among other things included the wiring...which my Eagle Cap 950 currently plugs into.

What it doesn't apparently have is a battery isolator. Something I thought would be included in this package. The Eagle Cap does not have one either.

When I pull the battery disconnect in the EC, I still read the RAM voltage.

Where would I install the isolator in this config (RAM has two batteries)?

Or should I just install a knife switch at each starter battery?

7 Replies

  • I used a single rectifier from POWER-GATE. Just plain works and is so easy to install.
  • egarant wrote:


    Hey Portscanner,

    That sounds like a great idea! I would be most appreciative if you can forward that info to me.

    Thanks!!


    I got one of these.


    The umbilical cable on my camper comes in right next to the fuse panel. I disconnected the 12V wire that comes from the umbilical from the fuse and connected it to one the top (large) terminals. The second top terminal is connected to the fuse where the 12V wire was originally connected.

    The wire from the umbilical that feeds the running lights is connected to a fuse. I ran a wire from the far side of the fuse (not the side the umbilical is connected to) to one of the small terminals near the bottom of the relay. In the (doubtful) event the coil shorts out, the fuse will blow, protecting the truck. Then take the other terminal on the relay to the - side of the 12 volt system.
  • okan-star wrote:
    Ive had hellroaring battery isolators before , which sense your truck ignition and open the link between camper and truck, but isolaters in general rob a little of the charge power your trying to use on the camper to run the isolater. Not sure if hellroaring is even made anymore , it was the best back in 06
    I use a simple solinoid ahat can be picked up at any rv parts store, its the cheapest , about 20.00 , way to go . Charge power in terminal, and out terminals , and a smaller terminal that when hot is conected to it opens the solinoid and lets power run thru,you connect this to the ignition wire on the truck , on Dodge can be found in fuse box under hood. There are models with ground terminals and without.
    Ignition on power runs to camper . Off it dosent
    I would abandon the factory wire for hot unless its at least a #10, and run new #8 from one battery terminal thru a thermal breaker and to the solinoid then to the plug to 5th - camper
    Or you could just find the hot 5th -camper wire and cut one in


    I hear you regarding the weak hot wire, I ran 6 ga. directly off of an isolator from my altenator to the house battery in an earlier set up. You loose a lot with the smaller wire. I am not as concerned with charging the house batteries as I have 260 watts of solar on the roof as I am to draining them when using my 2000 watt inverter......

    The wiring is a bit more complicated in the newer vehicles then it was in my 96 RAM.
  • Ive had hellroaring battery isolators before , which sense your truck ignition and open the link between camper and truck, but isolaters in general rob a little of the charge power your trying to use on the camper to run the isolater. Not sure if hellroaring is even made anymore , it was the best back in 06
    I use a simple solinoid ahat can be picked up at any rv parts store, its the cheapest , about 20.00 , way to go . Charge power in terminal, and out terminals , and a smaller terminal that when hot is conected to it opens the solinoid and lets power run thru,you connect this to the ignition wire on the truck , on Dodge can be found in fuse box under hood. There are models with ground terminals and without.
    Ignition on power runs to camper . Off it dosent
    I would abandon the factory wire for hot unless its at least a #10, and run new #8 from one battery terminal thru a thermal breaker and to the solinoid then to the plug to 5th - camper
    Or you could just find the hot 5th -camper wire and cut one in
  • portscanner wrote:
    As you discovered, Dodge does not turn off 12V feed (some manufacturers do.) As I did not want to give Dodge an excuse of "you modified the truck - your warranty is void" I found the 12v wire from the pigtail inside the camper and installed a relay to isolate it. I tied the relay coil to the running lights in the camper.

    Start the truck - running lights come on - 12V is tied in by the relay. Turn off the truck - running lights turn off - 12V is isolated.

    If you want, I can dig up the info on the relay. I got it off Amazon. Took me all of 15 minutes to install it. Never have to worry about leaving switch on and killing the batteries in the truck


    Hey Portscanner,

    That sounds like a great idea! I would be most appreciative if you can forward that info to me.

    Thanks!!
  • As you discovered, Dodge does not turn off 12V feed (some manufacturers do.) As I did not want to give Dodge an excuse of "you modified the truck - your warranty is void" I found the 12v wire from the pigtail inside the camper and installed a relay to isolate it. I tied the relay coil to the running lights in the camper.

    Start the truck - running lights come on - 12V is tied in by the relay. Turn off the truck - running lights turn off - 12V is isolated.

    If you want, I can dig up the info on the relay. I got it off Amazon. Took me all of 15 minutes to install it. Never have to worry about leaving switch on and killing the batteries in the truck
  • I would just install a Perko battery switch on the camper before the battery. They are the most reliable way to achieve the task.