Starting Engine with House Battery on SMB with Isolator
I am running a 2003 E-350. 12V electrical system only, no inverter. Isolator, not separator. Lifelife 4D battery.
My understanding is that with an isolator, it is not possible (given the factory setup) to start the engine with the House battery. SO - if I'm out in the middle of nowhere and my Starter battery dies, it would be no help to me that my House battery is still pumping 12.5V. First off, do have this right? Secondly, what have other folks with my setup done to get around this? Right now I'm thinking a set of 20-foot long jumper cables (and removal of the cabin floor to get to the House battery) would be the best way to get the job done. Any cleaner/smarter solutions out there that don't involve installing a separator or hauling around 30 lbs worth of jumper cables?
Sorry if this is a repeat thread, but I searched and couldn't find the info I needed.