Renault alternators, especially on 1.5 dCi diesel engines and 1.2 TCe petrol engines, are known to have voltage regulator issues. The regulator may allow voltage spikes above 16V or drop below 11V under load. A simple output test may show 14V at idle, but under load (lights, AC, rear defroster), the voltage may collapse.
Inspect the specific ECU fuses in the engine bay compartment. dtc p0560 renault
Worn alternator brushes, a bad voltage regulator ($20–$50 part), or a slipping serpentine belt. Renault alternators, especially on 1