I don't have experience with this particular error on this truck. But had similar errors on a 386 model.

The manuals say check the wiring: charging circuit, etc. Could be a bad battery / bad connection/dry cell (checked that? try with an other battery!).

But probably the capacitors in the LAC are bad; charging them takes too long. I once opened a power module and found some loose soldering of the capacitors.

Oh, and I had a truck on which a working light was connected after the line contactor: it didn't start when the working lights were on.