Having problems with the Temp Gauge not working. I have replaced the sender at the coolant outlet, checked continuity (ohms) on the single wire from the sender plug to the instrument cluster (0 ohms), ran wire from the 'B' Lug for Temp gauge to ground, needle moved. But gauge still doesn't work. Also have problem with the Thermal Temp Sensor for the ECM. Checked the 2 wires for continuity (0 ohms), cleaned all connectors. the engine has a slight backfire through the exhaust when decelerating and all trouble-shooting sources indicate the Thermal sender. It's been changed also for a new one. All suggestions welcomed, thanks.