It is constantly saying Self Call 7 and Self Call 3. Than it says service required. I will turn the truck off or disconnect and turn back on and it will work for about 5 minutes and the same thing happens. It blinks Self Call 7 or 3 and says service required. I called Bel and they said to send it in but I would be out of a detector for 14 days. If anyone knows any way I might be able to fix this. Thanks!!!!!!