Wurlitzer 720b LED Mod

[TooManyKeys]

Hey folks, I'm fairly new to both the forum and electronics. Has anyone had success replacing the original incandescent power light on a Wurlitzer 720b or 140b with an LED? I would value any input! I have followed the Vintage Vibe installation following their guide: cut out the 18k resistor at the terminal strip and jumpered the first two tabs, ran the grey wire from the 4-pin harness to the positive lead on the LED, negative to the red wire from the volume pot and grounded the negative to the braided shield on the 4-pin harness.
The LED does not turn on, and this configuration seems to leave my amp permanently on. Any thoughts?
Thanks in advance!