Twoxentrix, yeah I have a air compressor as well. I was going to head over to the van tonight to try and trace the cable from the isolator/solenoid. Ill start there and see if I can figure it out.
RE: Scalf77, I definitely see the concern and agree that 4/0 is impractical and unlikely for this installation. A couple things to mention is that unless I wake up stuck in the mud there is a good chance that between the solar and the alternator charge from the Blue Sea while driving I will be well over 50% battery life by the time I need the power and secondly I noticed here
http://assets.bluesea.com/files/reso.../990180180.pdf that the cranking amps (even at 1 min) are significantly higher amp ratings even on the smaller wire which in theory means one should always try to lesson the power needed by using snatch blocks and keep the power draw intervals to 30 seconds or less. Obviously in a perfect world this makes sense but we all know how it goes in real life
I'm going to check their wire sizes tonight and make the decision.