durn. there is so much about these trucks that is simple. Thats what attracts me opposed to my new 2018 truck. If you get a new ALT , get a one wire. Try and eliminate all the extras. Dummy lights and fuses. Yeah thats to much Volts to charge. Did you check the fuel gauge and sending unit together? Pull the unit out, hook up to the gauge and ground to the dash.
~ BD. "You won't find me in an old folks home" Pioneer Florida Cracker 1958 Apache Stepside 1958 Apache 1/2 ton Panel 1959 Apache 1/2 ton Panel