Lummox

I recently had a Toad Ai606 alarm fitted and I keep getting false alarms with it.

Sometimes when I arm the system it either beeps five times, or beeps continuously before sounding the alarm even though all the doors and windows are closed. Other times it arms like normal, but the alarm sounds shortly thereafter for no apparent reason.

I have noticed occasionally that the LED on the dash indicates that a door is open when it isn't, I believe this may be a problem with the tailgate sensor as the car's own door open light comes on occasionally when the doors are closed. I've gone round the car giving the doors a good shove and noticed that the light goes off when the hatch is shut hard.

I'm thinking that the boot sensor is probably the cause of the problem, but I couldn't find a switch like the doors have. Where's the sensor, and how do I clean/repair/replace it?

Thanks

ETA the car is a 1999 pre-facelift hatchback