I'm told Actia informed the last couple of inquirers they have quit servicing these gauges, but that's not confirmed by me as yet.
Just for grins, I'll check the wire loom diagrams to see where the two wires that attach to the sender terminate on their opposite end.
You can make that diagnosis definite by doing a gauge swap at your next rally. We've done that a couple times to isolate whether its in the gauge or in the coach some place.
Baja-tested '08 2-slide 36'
Alpine: The Ultimate DIY'er Project