Go back to the basics. The wiring from the starter solenoid to the alternator was smoking and or burned out the fusible link. Only several things can cause that;
A shorted alternator + terminal.
A short or pinched wire leading to alternator + terminal from starter solenoid.
The battery was hooked up backwards.
All this can be easily checked without letting any more smoke out by using an ohmmeter. It can be used to check the wire leading from the starter solenoid to the alternator, thus also checking to see if the wire going to the alternator is shorted. This can also check to see if the alternator is shorted. It will also let you know if the fusible link is open (good chance it is if it smoked).
And lastly used in the volts mode you can check the polarity of the battery to make positive is actually positive (rare to have reversed polarity battery).
My educated guess is you hooked up the battery backwards. Be forewarned, if you did that even for a second, it will cause the diodes in the alternator to short out and stay that way. Disconnect the wire from the alternator (make sure it is not touching ground, tape it up). Then connect the battery up, just brushing the negative cable on the negative terminal. There should just be little sparks, not arc welding or smoke. Turn everything off in the truck first.
If that goes ok, take the tape off the wire that went to the alternator and check to see if you have voltage there with a test light. If you do the fusible link is still ok.
If you have big sparks, disconnect the wire from the starter solenoid leading to the alternator. Then try connecting the battery back up. If it is ok then the wire leading to the alternator is shorted somewhere.
Then disconnect the battery again and connect the alternator back up. Now try brushing the – battery cable against the – battery terminal. If you have big sparks and possible smoke the alternator is shorted.