i've got a sport compact msd ignition and a friend put on a blaster 2 coil... Now all of a sudden the cars battery wont hold any charge and sucks mad.... before it had a blaster SS.... can the coil be too big be shorting out something or doing anything to harm something? (im not good with stuff like this)

 

any help?

 

Find out whether it's a coincidence... Disconnect the battery cables overnight. If it STILL loses the charge you know it's the battery's fault.

If it holds a charge disconnected, then you have to find something that doesn't turn off. Since you just installed the coil (& anything else new??) that's probably where you should look for something hooked up wrong.