Thanks for the reply. The PCB is grounded and the PIC sits within 1/2" of the regulator. I think I have the output portion of the capacitor issue down now but more about the input side. If, for example, I don't have anything on the input side....the car battery is going straight to the regulator, can this damage the regulator? Is the only negative effect noise on the line? I was thinking of adding a 10uF tant. and a .1uf on the input and output, do you think this would be good? The regulator is rated for 500mA and the peak current of the board is 200mA. The nominal current is 10mA and the peak is only seen when the alarm is activated, which hopefully should be never. Thanks again for the reply.

Chris