I just recently bought a pioneer avh5000 and I know this isnt in the right section but I was wondering if there is a way to bypass it. Any help would be appreciated.

Parking brake wire needs to see on-off-on to ground. Use a toggle switch or a relay

Oh yeah... I totally forgot about that! Sorry about the dead end PM lol. Yeah... the parking brake needs to see a sequence of ground/no ground/ground. Like if it were actually hooked to your parking brake, you would have to engage, then disengage, then engage again the parking brake. You can use a toggle switch to replicate this effect. Just put in a toggle switch, wire thew parking brake wire to one pole on toggle switch and the other pole on the toggle switch to a ground. Then simple flip the toggle switch ON/OFF/ON and the unit will be bypassed. You will have to repeat the process every time you power on the unit so the switch should be easily accessible.

Could the ducatiboy light flasher circuit be re-wired to send the required ground (-12v) pulses to the parking brake wire rather than (+12v) pulses to the illumination wire?

Sure. Or a TR7