fan blower working on setting 5 usually is the fan resistor. its located by the fan under the pass side dash.
your friend jumped the starter solenoid to get the starter to work, so im thinking you have a bad battery cable, bad ground or dirty battery terminals. <<<this usually cause just a click and then dead/ no dash power or nothing until you turn the key back to off.
after checking/cleaning the cables. next step could be the ignition switch, but im really leaning to towards the cables being bad, especially if its been sitting a long time.
and thanks for your service.