just put the dash back on my 12 started it up to check amp gauge and the key switch wont shut it down .checked the wiring diagram but was not sure which one grounded it out .read something about gronding the wrong wire on this system and you fry things.
If you are running a Tecusmeh with the SSI ignition, yes you can fry the module if hooked up wrong. I have a picture of a switch from a Sears that uses same ignition, not sure if it will help. There should be a black wire that comes off switch going down to behind flywheel which kills juice to module. sometimes they have another plug connection in the line, maybe it came lose. While removing dash, you could've possibly knock something lose inside of switch, but usually when that happens, a bad switch prevents having fire.
Here is my switch for the SSI ignition, maybe same as yours. If not, post up a pic if you can and we can help. The single spade is hte M or magneto kill wire on this switch.
The G terminal needs to be hooked to a good ground as when the switch is turned off, It connects the G & M terminals and kills the spark. (Check the switch with an OHM tester or battery powered test light..)