Lexus LS Poor Starting

I have a Lexus LS too. I had a similar starting problem that turned out to be a faulty charging system. Have you checked the alternator output and the wiring harness to the battery? Also, check the starter motor circuit.

Thanks. Can you explain how you diagnosed the charging system fault and if you had any circuit breaker or ignition switch problems?

The battery kept draining overnight. A parasitic draw test showed a faulty voltage regulator in the alternator. I'd get a professional opinion. The repair cost me 290€.

Thanks for the info. I'll schedule a workshop appointment for a charging system diagnosis.