No power?

i got a 1980 Rabbit FI it recently had the spark plugs, battery, fuse box and batterycables all replcaed ran almost perfect than the exhaust pipe broke off the which made it loud of course, than the manifold regulator switch (i think thats what it is, the thing that regulates how much the manifold opens up) broke but got it fixed than the alternator arm snapped off the engine on the highway, but the car still worked than one day bam its dead. while it was parked because of the alternator arm. But it worked perfectly before.