Late response, so you’ve probably already solved, but you just need to give the system 12v for a bit to wake everything up. I used one of those portable battery jumpers to wake mine. Could also just use another battery.
Some solar controllers also have the ability to supply power into any otherwise "dead" load, for this reason.
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N8SRE
1990 E-250 Sportsmobile w/ penthouse top, converted when new by SMB Texas.
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CSC TT250 + homebuilt trailer
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