Review on 🚗 Xpress DX345 Car Alarm: Programmable Hijack System, Trunk Release, Auto Central Lock, 3-Channel Alarm System by Dennis Brinson

Received this car alarm a few months ago and am trying to install it. Here are a few issues. The first of my cars is a Ford Van E150 without central electric locks (it doesn't have electronic locks). According to the instructions, I need to use the extra cable (+,-, power supply) that comes from the box (maybe my box is incomplete?!?!?!), so if I want to install it, I need to buy it, but where ? I can't find it anywhere! Second, I don't use my car alarm because it only works for 30 minutes and then everything works! I know I'm not a professional installer, but people in the shop can't find the problem either! In closing, CAN YOU PLEASE HELP ME SOLVE THESE TWO PROBLEMS? SOMEONE PLEASE. PS My email is kda.84@mail.ru Thanks in advance!