We had a battery issue, unplugging the smart charge connector saw the battery charge, although at 14v, and the light go out irrc, turned out to be the smart charge on alternater after much messing with wires etc trying to find the issue as Many said it would be this that and the other, but if it was me, I would start with the alternator replacement. Was an easy job if a little tight, we wrestled it out rather than removing too much.

Why have you ordered a new loom?