Electrical mayhem.....HELP???

i have a question for the experts on here.....here's my list of symptoms....these symptoms ALL started after i put in a set of those SHITE Gen 3 dual halo projectors....the ones that just plug into your stock harness BUT DON'T have an additional line to connect with the battery....

1. the speedometer is flying around all over the place. This will happen when i'm driving, or when sitting still and just revving the engine....this also happens when the lights are off or on....

2. the lights begin to increase and decrease in brightness IN TIME with the engine doing this idle high, idle low alternating thing.....this happens with the interior lights as well as the headlights....this happens to the interior lights even when the headlights are off....

3. the halos on the passenger side lights did not work when i first put the headlights on, but they worked on the driver's side....

MY THEORY:

1. the dual halos are shite and have a short in them somewhere.
2. when i put them on and began to drive the short in them sucked power and blew the alternator somehow.

MY SOLUTION:

1. buy some decent headlights and a new alternator?????

THANKS IN ADVANCE FOR ANY ADVICE....PEACE...MC :smokin: