Tailgate open indicator

Alhambra 1.8 20VT 1999

Hi, the dashboard tailgate open lamp on my Alhambra is showing open even when closed, it causes the alarm to go off intermittently! I've stripped out the tailgate lock mechanism and disconnected the wiring for the microswitch but it still indicates open, a dead short on the wiring loom makes the indicator a little brighter. I've also checked the wiring through the flexible boot into the body of the car but it all looks fine.

Does anyone know where these wires route or where they connect to? I've looked under the passenger seat and there's no box, just an empty space.

Thanks in anticipation.:confused: