Originally Posted by grandriver125
Finally found exactly what I want and will hope to get one in the next week or so (have to get it across the border).
It covers off the fuse and diode. It also provides a short instructional video. We will not put a connector in the front of the vehicle but will runt the wire right to the 12V pin on the 7 pin connector on the motorhome.
RVibrake Towed Battery Charger, charge line replacement
It's your prerogative to spend $50 for a fuse & holder, a diode, and 8' of 16 gauge wire.
You may want to also provide your son with the following information; much of which he probably already knows:
- The MH alternator with voltage regulation (i.e. the motorhome's charging system) will monitor/regulate the voltage and generate the current necessary to keep the toad battery charged.
- Your Itasca probably has a switched 12 volt feed (my 2010 Itasca does) which means you do not need a diode to save your toad battery draining back into the MH battery. IOW, the 12 volt feed is made by a relay that is only closed when the MH ignition is turned on. When the MH ignition is turned off, the 12 volt connection is severed; no way for the toad battery to drain into the MH battery. BTW, there is a cost in using a diode for battery isolation. My understanding it is .7 volt. That's .7 volt less pressure available to do the job.
- It's likely your MH socket has a fuse or breaker protecting the MH side of the connection.
- Your MH's 7-pin socket has a ground prong at 7 o'clock and a 12V+ prong at 1 o'clock as you are facing the socket.
- FCA's Accessory Kit to Enhance Flat Tow harness uses a 10 amp fuse to power up the Electric Power Steering. Using that estimated draw plus the draw for the tail/brake lights and potential toad battery draw, I doubled it to 20 amps max draw. 16 gauge wire will handle that for the about 10 foot stretch of umbilical cord, but I used 10 gauge because it's cheap. Did that for both the negative and positive wires between the MH and toad.
- I bought a marine-grade 10 gauge waterproof fuse holder and a 5-pack of 30 amp fuses for $10 Amazon. That goes in line close to the toad 12V+ battery connection.
My charge line cost me $10 (I had 10 gauge wire laying around my garage) and I would argue it is better than what you will get with the $50 product.