My BATTERY SWITCHES in my RV TRAILER setup is all in the POSITIVE SIDE of the 12VDC runs. This was the easiest way out for my BATTERY selection and disconnect plans. This idea is great for multiple battery banks allowing you to use none, one, or all of the them for your RV Trailer battery supply.
However if this was the TRUCK START BATTERY/ALTERNATOR circuit which you may be describing then I will go with MEX and only switch out the NEGATIVE terminal.
I know in my FORD TRUCK alternator setup the few time I had to disconnect the start battery battery from the alternator I always end-up resetting all of the truck computers and have to go thru a new system learning time for all computer controlled things to get back to normal. My truck seemed to never re-learn the idle speed when stopping at a stop sign and my truck would die every time. Then I have to go to the Ford place and put it on their machine to set the values and that of course would be a minimum $90 charge. I am very hesitant of removing my truck start battery terminals at all for this reason...
The RV TRAILER side batteries is a totally different story for me...
Roy Ken
