Wiring a camper battery

[rthomas]

I sold my 97 Ram that had a relay that the camper dealer installed, which I guess activated off the ignition. So on my 03 RAM 3500, where do I find an ignition on wire that I can splice into a new relay for the camper? This 12V wire would probably have to be 12 or 10 gauge because besides charging the camper battery, it also feeds the refrigerator. Previous posts have suggested using a diode isolator, but I would prefer to use a relay.

 

[Loren]

Ron,



There are some problems with doing things the way you suggest.



First, you do not want the wire that supplies DC power to the refrigerator to be controlled by the ignition or else your refrigerator will run only when you have the ignition on. Unless you drive a lot more than you park, your food will spoil. Most RV refrigerators use AC electricity or LP gas to cool, but they require DC power to control the system.



Second, you mentioned that you were going to control a relay. In this case, all you need is a signal to the relay to close when the ignition is on. You do not need a large wire. A common source for an ignition on signal is the cigar lighter wire, or its fuse at the fuse panel.



Third, the actual power wire to the camper should be large enough to carry the load. It should come directly from the battery, or an equivalent. The hot (battery charging) wire that is at terminal 4 on a factory trailer plug should work if you don't want to install a new wire.



Good luck,

Loren

 

[AClayton]

My . 02 as well!!



Alan

 

[Grizzly]

I have always felt that an isolator is the preferred way to go and if your refrigerator is a 3 way, AC, DC and propane, a 10 ga wire is a must or you could fry or trip something.