I currently have a VDO Cockpit Black electrical temp gauge with the sender tapped into the waterpump housing. It has always read about 20 degrees too low (based on when the fans turn on) and I'd like to adjust it so it reads exactly 221 when the fans come on low, and 180 when the thermostat opens. Does anyone know if I can simply add a resistor in series with the gauge to get it to read higher? And if so, what kind of resistor would I need? I basically need the specs on the sender, I couldn't find it on the VDO website and their response to my question is pending. TIA guys.