Removed glovebox(best accomplished with a sturdy axe). i97 directly behind, attached to 50(?)mm tubular steel xmember. Unplugged, examined. Clean as a whistle. Reconnected. Examined 2 earth points near transmission selector. Not a molecule of corrosion. Reattached. Removed cluster(multi instrument). Unplugged connector RHS. Observed slight amount of semi liquid black insulationy type stuff. Re-connected plug. Normal function of everything observed.
Thanks to all for suggestions.