Mystery smoke from gauge cluster

Dana67Dart said
If the dash was not grounded there is no path for the IVR to function correctly so it just provides 12v to the gauges.

You probably overheated the gauges and that was the smell and smoke.

They may still function ok.

That makes a whole lot of sense, that could be why it was intermittent and took a while to start smoking. I'm going to inspect it before I put it back in, I'm getting ready to put a new headlight switch, bulbs and fuses in anyway