2004 Vogue parking sensors problems

[nakedguy]

I fitted a tow bar this week which involved removing the back bumper. Not a particularly difficult job but it meant disconnecting the rear parking sensors. I unclipped the plug under the panel in the boot space, not a problem. However since putting it back together they dont work. When switched on the light on the switch flashes for a bit and it beeps for a bit then stops. Neither the front or rear seem to be sensing. I checked the plug (twice) but to no avail. I checked the fuses, everything ok there.
Has anyone else experienced this and is there something I need to do to reinitialise them or something.

Thanks

[S26VE P]

Cant help sorry, have you tried here http://www.fullfatrr.com/forum/index.php