I think this is why.......

[unclebob]

Pretty sure I've found the reason for the charging wiring kluge! I had been able to see the end of a big heat sink like those on solid state battery isolators, but access was impossible 'til I removed the headlight bucket and moved the horns and all the wiring for the area. It was an isolator. buried under a pile of damp debris, with the heat sink fins stuffed with more junk. The driver's side front of the engine compartment, under the battery tray and behind the headlight cannot get much air circulation anyway, but add years of accumulated dirt, leaves and "stuff" that settled out of whatever air flow there was and there's a recipe for electrical problems. Even the cooling fins on the bottom of the isolator were full of that trash, and the nuts and crimp-on ring connectors were corroded so badly that I broke all three of the bolts off of the isolator. And that's after hours of soaking with penetrating solvent and trying to work the nuts gently back and forth. When they moved, they were broken!

This leads me to conclude that the isolator failed and a previous owner abandoned it and constructed the wiring disaster I inherited. I'm going to have to drill out the corroded mounting screws for the isolator and circuit breaker and start over with a clean working area for a new isolator. If I was going to replace the solid-state isolator with another of the same type, I would build some stand-offs to raise the isolator an inch or so and maybe drill some holes in the sheet metal in the area for better airflow. I'm going to use a relay-type isolator instead, because it's totally enclosed and doesn't need heat sinks.

Ain't progress wonderful?!?!

BC

[AK49er]

Not sure if this would help you but our later model Dodge has the Isolator mounted at eye level in the engine bay. It is mounted topside of the compartment, clean and out of the way. Maybe you could relocate yours to that area for better airflow. Anyway, that was just a thought.

[booster]

If your are considering a separator instead of an isolator, you may want to look at some of the electronic switching ones, instead of the relay type. Most are referred to as ACRs or automatic charging relays. We have a relay type on our 07 Roadtrek, and I can tell you the coil gets very hot, and it pulls significant power of about 1.5 amps when on. In the upgraded charging section, we have a pair of Blue Sea electronic type separators that hardly get warm at all, and you can do a force disconnect on them just by putting 12v through a switch to the start isolate circuit. Very handy to keep alternator high voltage off the coach battery if it is already full. They draw very little power.

http://www.bluesea.com/products/7610...12_24V_DC_120A

Other manufacturers also make similar products.

[unclebob]

I bought this one: Smart Dual Battery 140A Isolator - Auto/Boat/RV
http://www.amazon.com/Smart-Dual-Batter ... y+isolator
I really like the looks of that Blue Sea unit and I've not heard anything bad about their products. I just saw the TrueAm one first, and it'll mount up high above and behind the vehicle battery on the firewall. It's got a flashing led status indicator, too! Be a shame to hide it under the battery, wouldn't it?
It does seem kinda odd, though, neither their wiring diagram or instructions shows or mentions relays or fuses in the wiring
BC