Taurus Ignition Fault

Terminal 15 relates to the switched positive voltage supply, so a defective cable or plug connection is plausible. Have you checked for voltage drop along the wiring harness to the starter solenoid? It could be a break in the circuit, like a kink in a garden hose. Also, inspect the fuse box; a blown fuse could cause this.

Thanks. Could you elaborate on the specific points I should test when checking the wiring harness for voltage drop? Are there any known weak points in the 2016 Taurus wiring harness that are prone to failure? I want to be thorough.

Without the specific wiring diagram, pinpointing exact test points is difficult, but focus on connections, especially near the starter and ignition switch. Given the symptoms, a complete break is unlikely; more probable is increased resistance due to corrosion or a loose connection. Check the cable leading to the component itself. If you're unsure, consider a workshop; diagnosis can be tricky.

I appreciate your advice. I did a more detailed inspection and had to bring it to the workshop. It was a defective plug connection within the wiring harness, as suspected. The repair cost 95€. Thanks for pointing me in the right direction.