I had the same problem a long time ago when we had an '86 Prelude. It
happened whenever I replaced the multifunction stalk on the steering
wheel column. When I plugged the new wire harness into its mate on the
firewall, I inadvertently bent one of the pins just enough so it did
not go into its socket. Took forever to figure it out, as it is in a
tough location to see. Hope this helps!