Back to working on my Jeep. I've run into a problem with dead batteries after a long period of flat towing the Jeep behind the motorhome. To flat tow, the Key must be in the RUN position so the steeing wheel is unlocked, allowing the front wheels to track. This of course means many of the accessories are energized. My first thought was to just disconnect the batteries. Tried this a few times. It works but it makes the whole connect/disconnect process a bit tedious. Right now I have a 4-wire hook-up that runs only the tail/stop lamps. It occurred to me, if I upgraded to a 7-wire setup (on the Jeep side) could use the two DC outputs (B+ & Aux) to help keep the battery system charged. Both outputs in the motorhome are 30A's. Once I started working on the wiring, I realised I probably want ensure there's no backfeed from the Jeep to the motorhome. I have 1-2 diodes for the lights. Would one of these work for the power feed: Solar Diode?

Thx, Joel

 

Back to working on my Jeep. I've run into a problem with dead batteries after a long period of flat towing the Jeep behind the motorhome. To flat tow, the Key must be in the RUN position so the steeing wheel is unlocked, allowing the front wheels to track. This of course means many of the accessories are energized. My first thought was to just disconnect the batteries. Tried this a few times. It works but it makes the whole connect/disconnect process a bit tedious. Right now I have a 4-wire hook-up that runs only the tail/stop lamps. It occurred to me, if I upgraded to a 7-wire setup (on the Jeep side) could use the two DC outputs (B+ & Aux) to help keep the battery system charged. Both outputs in the motorhome are 30A's. Once I started working on the wiring, I realised I probably want ensure there's no backfeed from the Jeep to the motorhome. I have 1-2 diodes for the lights. Would one of these work for the power feed: Solar Diode?

Thx, Joel

I rather use something with a low voltage drop.
Low Voltage Drop

 

Welcome to AAC.

If disconnecting the battery doesn't have any adverse consequences (e.g.: computer reset, radio reset, &c.) then the inconvenience of disconnection is easy dealt with by something like this.

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There are many variants if this device, you can pick one you like.

If disconnection does cause problems, you could switch between your starting battery and something like a LiFePO₄ "drop in" 12V deep cycle battery and a small solar panel. This would maintain all the computer and electronics related functionality without a constant low-level drain on your starter battery, for which it was never designed.

 

Welcome to AAC.

If disconnecting the battery doesn't have any adverse consequences (e.g.: computer reset, radio reset, &c.) then the inconvenience of disconnection is easy dealt with by something like this.

View attachment 355888​

There are many variants if this device, you can pick one you like.

If disconnection does cause problems, you could switch between your starting battery and something like a LiFePO₄ "drop in" 12V deep cycle battery and a small solar panel. This would maintain all the computer and electronics related functionality without a constant low-level drain on your starter battery, for which it was never designed.

I have a set of switches similar to that. I used them for a while but they don't fit the battery post very well. I'd prefer not to have to open the hood if I can help it.

 

I have a set of switches similar to that. I used them for a while but they don't fit the battery post very well. I'd prefer not to have to open the hood if I can help it.

There is always something like this.

 

There is always something like this.

Looked at that too. I thind it would be overkill.

I already have a dual battery setup. I can isolate the batteries if needed (if I remember). But one will still run down. I'm thinking a "trickle" charge (especially for AGM batteries), controlled by the device recommended it post #2, would be a better long term solution. And, it will fit in the 7-way junction box I'm using.

 

To flat tow, the Key must be in the RUN position so the steeing wheel is unlocked

Isn't there a position between RUN and LOCK? It's been a very long time since I had a car with a key. Thinking back more than 10 years, there's an ACC spot between Run and Lock. Going even further back ACC was to turn the key backwards, but that's been a very very long time since I saw that. What year, make and model is your jeep?

 

Isn't there a position between RUN and LOCK? It's been a very long time since I had a car with a key. Thinking back more than 10 years, there's an ACC spot between Run and Lock. Going even further back ACC was to turn the key backwards, but that's been a very very long time since I saw that. What year, make and model is your jeep?

2014 JKUR. Ignition switch has OFF, ACC, RUN, START positions. Steering wheel is locked in ACC, unlocked in RUN. To prep for flat tow you turn the key to RUN, but not as far as START.

 

Here's another towed vehicle charger option.