You have 8 LEDs. Do they have Vforward of less than 1.5V? 8 x 1.5 = 12.
Usually with a 12V source, the most you can use is 4 or 5.
I would also strongy suggest a 0.1uF cap from pin 2, Vcc, to Gnd. Look like caps on their board (marked 103 =100nF caps), not diodes
This inverts the data going out?
~digitOne
as 1 into the shift register turns on the output.