Review on 🛰️ VDO 340 786 GPS Speed Transmitter by Eddie Duncan

As others have noted, no instructions are included. I called the VDO Techline and they were very helpful! Explains how to connect the module. In my case I'm using a VDO programmable speedometer, the red wire goes to 12 volts positive, the green wire goes to pin #8 on the speedometer, and the white and black wires combine and connect to ground. I programmed the heart rate setting on the speedometer to 200,000 and it worked great. I tested it in the MPH app on my phone and it certainly works!