relay help needed 73 vw bus

Well,where do I start.......I bought this vw bus from a guy a few months ago,he was selling it for the owner,the owner before him was an electrical engineer and looks like he had some time on his hands.He has set up my bus which I have appropriately named gadget.Well I picked up gadget for a pretty good price because the engine needed rebuilt.So a friend of mine rebuilt it for me but when putting the electrical back together things aren't running the way they were ..ie a couple of wires aren't connected or the relay is gone or not quite sure.I know some about electrical but this is a little much for me.So I've added pics to show the set up.First thing is that my batterys aren't charging properly or they are draining each other or there is a short or something.I have recently replaced the isolator b/c I thought that was the prob but now am thinking its on of the relays.You see in the first pic the iso/relay setup.So the batteries are hooked up to the relay,which then has wires attached to the iso,the alternator is hooked up to the iso.Could the prob be that the relay is stuck closed b/c it is set up kinda like an iso and so you will still get things draining?Or from the small little relay that is attached off the larger relay towards the firewall.When the engine is off ,I don't have a voltmeter unfortunately!!but when Iput my test light on the relay it lights up on both sides along with the smaller relay and the iso,should all of these be having power supply when engine off.Well I'm gonna stop here for now and hopefully someone can start to lead me into the problem solving..thanks in advance to anyone willing to help.73 vw_bus,(gadget!!)

This is what I attempted to send the first post but it was to big.So you can see the iso mounted and the I'm guessing is a relay set up so that you only drain from the aux batt. when camping.Then you see a blue wire going to what I'm guessing is another type of relay?So my main pos. is hooked up to the right side of that relay then two smaller gauge wires go to the iso far right post ,the aux pos. goes on the left of the relay and then again two smaller gauge wires going to the left of the iso,the alt. is hooked up to the top post on the iso.73 vw_bus,(gadget!!)

man you need to rip that out! and start again before you get a fire.make sure that it is fused also.split charging systems do not cost much atall.you can fit a new one for the price of a tank of gas

So this is the back firewall,ya I know holey moley!!!Well for me anyway,but ya on the left hand side there are two grey wires that are heading back to that relay which are splissed into the small gauged wires that go to the iso,and these are labelled on the firewall aux charge and main charge.73 vw_bus,(gadget!!)

Well I figured that I placed the alt connection in the wrong place it should be on the pos. post on the main battery,and I found the three way switch for the solenoid itself hidden in the engine compartment.I'm going to try to recharge the aux batt and test to see if I can get things goin,I also noticed that the solenoid does not have a groung cable off one of the small prongs.73 vw_bus,(gadget!!)

Well I've noticed something else as well there are four prongs on the iso/solenoid the two main and two small usually one for ground the other for ignition right well when the engine is off there is power on one of the small posts,does this mean that the solenoid is blown,b/c I beleive that is not supposed to be power there right?73 vw_bus,(gadget!!)