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Jim
Jim, ASE Certified Technician
Category: Lexus
Satisfied Customers: 1257
Experience:  AAA Repair Shop Import Domestic Owner - Tech
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Battery no charging, alternator replaced and still not charging.

Resolved Question:

Battery no charging, alternator replaced and still not charging. Where or what should I look for?
Submitted: 6 years ago.
Category: Lexus
Expert:  Jim replied 6 years ago.

My name is Jim. First let's start with the wiring diagram and a few questions:

1. Does the charge light come on ?

2. Does it go out after the car is started?

 

Here is the diagram for your car : Notice you have 3 power supplies @ terminal 1 - 2 and 3. If you have the key on and engine off what is your voltage readings?

 

 

 

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Expert:  Jim replied 6 years ago.

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Customer: replied 6 years ago.
Jim, 1. Does the charge light come on ? The Battery Symbol is on when the engine is running 2. Does it go out after the car is started? It does not go out while the engine is running I'm using a digital meter and it show 11.65 Volts DC at the battery terminal as well as on the large copper post on the alternator. Here is the diagram for your car : Notice you have 3 power supplies @ terminal 1 - 2 and 3. If you have the key on and engine off what is your voltage readings?
Your diagrams are helpful Can you suggest the most likely place to look? Thanks, Rick
Expert:  Jim replied 6 years ago.

The most likely place to look : you will need to take your volt meter , disconnect the alternator connecitons and test for voltage as I described above. Be careful not to short anything out. If you do not feel you can do this then you will need to have it checked by a professional shop. I have checked out vehilces before for customers and they did their own repairs.

 

First check the fuses. If the fuses are good and you have voltage to the terminals that you need to check the alt is no good. Did your old alt have the light on? It is possible to have a bad rebuilt alternator. Jim



Edited by Jim on 7/30/2010 at 2:48 AM EST
Expert:  Jim replied 6 years ago.

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Above connectors G1 Battery Voltage G2 unplug alternator and check for voltage in pin 1 2 & 3 Key On Engine Off. What are your readings? I will check back..

thanks Jim

Jim and 3 other Lexus Specialists are ready to help you
Customer: replied 6 years ago.

Jim,

It turned out to be a "DOA" alternator, nothing more than that.

Installed another alternator and all is working as it was designed, bad parts can be difficult to prove.

Thanks,

Rick

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