"Raising engine to 3K dose not alter the output 12.6V steady." That sounds as if either the alternator or its wiring is duff. I don't know what was fitted to CSRs, but I'd start by checking all of the relevant wiring and connections including the engine earths. Inspect, wiggle, disconnect, clean, reconnect. That should identify the thin wire to the warning light and whether there's an exciting wire. Jonathan PS: Has the battery ever gone flat? And do you charge it whenever it's back at base?