sorry, the orange wire is just tapped going to the relay, it’s not cut. The black and green are not continuing past. So it still is the risk of double amperage?

 

If the lights come on when you connect the Orange wire at Switch #3 to power and those light don't come on (through the "Trailer tow relay, battery charge") with the key on, then it appears that the connection between the trailer connector Orange wire and the Orange wire at Switch #3 was disconnected somewhere (maybe at splice S118 in wiring diagram 95-2?????). If that's the case then those are now separate circuits and there would be no interaction so you'd be OK.

That leaves you to figure out the other wires you mentioned...

 

Well, checked that orange wire and it is wired in for the rear lights, but the rear lights dont work, probably something with a bad ground I believe. Tested the switch in on position with key off, the 7 way connector gets power, connector loses power when I switch it off. Turned ignition on, switch off, the connector got power also. Will be unplugging this wire and run a new lead to the back for the bumper lights and utilize this switch for the rear bumper lights, wired in properly.

Finally got to diagraming out my solar setup as seen here. Switch #1 controls the Isolator seen in the diagram. Any idea why there are two SMH style plugs in this system? One is going to the inside of the van, connected to the controller in one of the battery connections, and is labeled as "inverter". The other SMH plug was going to the roof and the Negative wire was shredded apart above the roof and full of corrosion.

Is this solar system set up properly as well to charge the battery being controlled by the switch on the isolator?

 

I have a bunch of questions and comments!
I numbered them so we can keep track as we discuss...

1. I don't see the second battery in your diagram.
2. Your diagram shows an inverter output on the solar controller but an earlier photo shows the solar converter with a second battery connection and no connection marked inverter.
3. Your diagram doesn't show any connection between the positive side of the van battery and the solar controller (even with the isolator on) so the solar could never charge the van battery.
4. The diagram shows the isolator connecting the "Battery" terminal on the solar controller to the red SMH connector. Not sure what that's about unless the red SMH is for a second battery?
5. The isolator switch is wired (as I expected) so the switch lamp is in series with the isolator coil. As I said, unconventional but OK if it works.
6. If there is an "Inverter" connection, it's connected to the gray SMH. Maybe for an inverter that could be easily removed from the van???
7. If your diagram is complete, the 50A fuse and 200A CB are in series so the 50A fuse will blow long before the 200A CB trips. Maybe the 200A CB is just being used as a disconnecting means and not really as a protective device.
8. If you provide a model number for the solar controller, I might be able to get some additional ideas.

 

Answered here:
1. I don't see the second battery in your diagram.
2nd battery if in series as part of the vans factory wiring. Nothing from the solar system is wired to any terminal on the 2nd van battery.

2. Your diagram shows an inverter output on the solar controller but an earlier photo shows the solar converter with a second battery connection and no connection marked inverter.
Yes, the controller battery output is labeled as "inverter" on the wiring connected to that output. "bat 1" on the solar controller is labeled as "inverter" on the wiring and this is the wires going to inside the van to the gray SMH Plug.

3. Your diagram doesn't show any connection between the positive side of the van battery and the solar controller (even with the isolator on) so the solar could never charge the van battery.
I just followed the wires on the setup that was part of the van when I purchased it and diagramed them. Im trying to figure out what a previous owner did and fix any errors.

4. The diagram shows the isolator connecting the "Battery" terminal on the solar controller to the red SMH connector. Not sure what that's about unless the red SMH is for a second battery?

5. The isolator switch is wired (as I expected) so the switch lamp is in series with the isolator coil. As I said, unconventional but OK if it works.

6. If there is an "Inverter" connection, it's connected to the gray SMH. Maybe for an inverter that could be easily removed from the van???
This is what my thought was.

7. If your diagram is complete, the 50A fuse and 200A CB are in series so the 50A fuse will blow long before the 200A CB trips. Maybe the 200A CB is just being used as a disconnecting means and not really as a protective device.
Yes the diagram is complete. There is no other wiring as part of the system, I disconnected each wire and did continuity testing at each end to find the path each one takes.

8. If you provide a model number for the solar controller, I might be able to get some additional ideas.
1204epipdb-com I belive. just snapped a photo of the sticker on it here.

 

There is no connection between the truck batteries and the solar system which means the solar panel couldn't charge the truck batteries. That says to me that one or both of the SMH connectors have to go to batteries.

Because there's no interconnection, the alternator also couldn't charge any batteries connected to the SMH connectors

If the gray SMH connector went not just to an inverter but a battery and inverter set then that battery (I'll call it the inverter battery) would charge from the solar panel and would supply the inverter.

If the red SMH connector went to a roof mounted battery, then that battery would also charge from the solar panel as the #2 solar controller battery. The roof battery (as solar battery #2) would take only a portion of the solar panel power as divided by the controller. In that case, the isolator would disconnect the roof battery meaning the solar controller would not see a "Battery #2" and, according to the controller manual would send all solar cell power to the inverter battery.
Don't ask me what the battery on the roof would be for.

I don't think I can get much closer to what the previous owner was thinking.

So, now the question is what do you want the batteries in the vehicle to do? What charges from the alternator, what charges from the solar panel?, what is the use of any additional batteries (beyond the truck batteries?, do you want to get into separating the two truck batteries and making one a "house battery" so you can use that while parked without killing the main battery? Do you even need the solar panel? Etc., Etc.

 

Upon random research and chatting with others, I believe that the rooftop connector was for a rooftop tent as many have that connector for power to the tent. I am leaning towards setting up a 3rd "house" battery and putting it down on the frame near the factory battery. This way I can properly set up the battery isolator, have an inverter and charge the house battery with solar. clean up the previous owners weird mess and make it a clean, logical setup. Appreciate the help on this hunt of wires!

 

Happy to help out. As I said, I enjoy the challenge.

If you come up with additional questions or just want to run your final circuit past someone, I'll be here.

Best of luck!