Lexus Alternator & Lexus Starter Motor Fault Diagnosis
If your starter motor is turning very slowly and your interior lights are dull then you may have a
faulty battery or the battery may be weak. To check this it is advised to take your battery to an auto electrician who can check it.
If you turn the ignition switch & nothing happens at all then you may want to check the connections
from your battery to your lexus starter motor. These sometimes get rusty and need cleaning.
If you turn the ignition and hear a clicking noise then your starter motor gear may be sticking.
Put your car into 4th or 5th gear, make sure your handbrake is off and gently push your car forwards and backwards. This sometimes releases the gear in the starter motor and lets you start the car as normal. The lexus starter motor gear will nead replacing at some point.
If your battery is not charging then you may have a loose alternator belt. If you hear a screeching noise then tighten your belt and then the alternator will charge your battery.
You can test if your lexus alternator is charging correctly by using a multimeter. Set the meter to DC current and connect to the battery terminals. Turn off all lights and interior electrics and rev the car to 2500rpm. The multimeter should read between 13.5 and 14.4 volts. The lexus alternator needs to supply more voltage than the rated 12v battery.
Remember if in doubt about your lexus starter motor or lexus alternator then take your vehicle to a reputable auto electrician who can diagnose any faults.