i have aftermarket central locking.. i bought it from brisbane car sound. me & my dad installed it. it worked great for 18 months, now, when i lock the door (i dont have remote, i have to use the key) the locks just pop back up again, so it is just continuously "lock, unlock, lock, unlock...." so i disconnected the central from the battery for now, as i didnt have time to fix it. is it just that the sender unit isnt grounded properly anymore?