Lost all gauges, preheat, and charging

[derek528]

I was testing some wires and accidently sent 12v into a 5v ground wire going to the computer, now the tach, speedo, grid heaters and charging systems are not working. I know I most likely fried the PCM, but I was wondering if it is possible that I just blew a fuse or something. I checked all of the fuses in the cab and the ones in the box under the hood, are there anymore fuses inline anywhere? Any ideas on things to check before dropping $ on a PCM?

Thanks, Derek