Speedhut line temperature gauges have a single yellow wire running from gauge to sender. For the sender and gauge to operate correctly, the sender must be threaded into something that is grounded to same grounding source as the Temperature Gauge. The ground path for the sender is the sender's mounting threads. Use teflon paste on the sender threads to make a good seal while maintaining a good ground connection. Do NOT use teflon tape (Teflon tape will not provide a good grounding connection)!
If you are having any additional issues with your Speedhut line Temp gauge or its sender please contact customer support.
