Primastar Overvoltage Faults

A discharged battery could cause overvoltage faults by failing to dampen voltage spikes. Have you assessed the alternator's output? An unregulated alternator may generate excessive voltage, damaging components. Also, inspect grounding points for circuit integrity, as compromised grounds can induce erratic behavior. Prolonged overvoltage can degrade the ECU.

Thanks! How do I test the alternator's output for overvoltage? Can I use a multimeter, or do I need special equipment? Also, where are the common grounding points on the Primastar?

To verify the alternator's output, use a multimeter to measure DC voltage at the battery terminals while the engine is running. The voltage should be 13.5 to 14.5 volts. Deviations may indicate a malfunctioning alternator. Given the complexities, consulting a technician might be prudent.

Thanks, I appreciate the advice! A local garage confirmed it was a discharged battery. Replacing it solved the overvoltage and system failures. It cost 290€ for the new battery and labor. Glad it wasn't more serious!