I am new and i posted one earlier but do not see it I will try again..

I have a 1985 f250 4x4 non turbo 6.9 in december the parking lights came on one night by themselves, so I got the truck started pulled up to the garage and pulled the lights on and everything shut down, the motor the lights, I thought well I 'll replace the light switch so I did, and nothing changed when the key is turned all the pre ignition sequence runs glow plugs and all but no start not even a click from the starter. so I changed the ignition switch sitll nothing, the parking lights still come on when the neg terminal is hooked up. Any help would be greatly appreceated.
Papa Chubbz