Well, turned out the short was in the alternator. So new alternator and all good.
Thank you for the assist. Learned a lot about the wiring is...
i’ll let you know how it goes. I am on the road next couple of weeks but, ill be sure to post when i fix it.
here is Vin 1FV6JLVC1SL65912
1994 FL80, cummings 8.3 e-One firetruck. Do not have manuals nor fuse panel diagram.
Turn key to off engine keeps running. Fuel solenoid...