The only thing I can think of is that might be wiring for the Homelink system. That feature was added in 97 to the Discovery. But you said yours was an SE7. It was standard on that model. Originally it was mounted over the drivers door (like on the P38 Range Rover), but it was moved to the area under the interior rearview mirror later. Is that were it is on your truck?
About the interior sensor on the DII... It is technically an infrasonic sensor. Too many people complained about it being set off when the vehicle was parked with the windows down or with a dog left inside. It was quickly discontinued (in 2000 or 2001). The movement of AIR inside the car caused by the wind blowing if the widows were down was enough to set it off. It can be turned off in 2 ways. One, it can be turned off by the dealer using TestBook. Two, if locking the car with the remote, pushing the lock button twice within 2 seconds. This will lock the doors and turn on the perimetric protection but not the interior protection.
Stephen
