dude....

its the tip-over sensor.

you can either re-install it on ur upper race plastics.
or
bypass it through the harness.

and just fyi, it has nothing to do with the headlights.

 

and easy way to do it...

(if you're not using the front harness...ie: signals, lights)

connect the red and the green together




or if you don't have a crocodile thingy, you can stick a wire/paper-clip through the other side of the harness.
make sure to use alot of electric tape to hold that bitch in place.

 

When you disconnet your Headlights, I'm sure you're doing it at the harness. The bank angle sensor wirirng is part of that harness, so when you unplug you're breaking the connection as Abadfish & Dirtytoes said. Best solution is to remount the bank angle sensor.


BTW- What do you plan to do with your OEM stuff?