Possible Alternator or something else?

[markw81]

I've got an issue with my 04 Camry that whilst I am in the drive thru, or in a slow shopping area car park (tight turning, slow idling etc), I have the charging system / battery light flash on and off intermittingly, but it won't ever come on whilst driving even when turning.

Given the age of the car I am mainly thinking alternator but I am wandering if there is anything else that could be happening or may need checking up on?   Whilst I definitely will do the alternator soon if there is something else I should be looking at it would be good to look at it.   Any other things like cords, connectors, belts?   The belt looks ok and doesn't have much free play in it.  No belt noise either.

I have put a multimeter on the battery and when car running it does go up to 13.7V.  And battery sits at 11.9V when off.

[campbeam]

8 minutes ago, markw81 said:

And battery sits at 11.9V when off

I am pointing the finger at the battery. It should be at 12.5V at least for a good battery. My previous battery [purchased May 2017] started to be unreliable not holding charge at 12.5V. New battery [now 1 month old] sits at 12.9V

https://www.centurybatteries.com.au/maintenance

[ozieagle]

The battery light flashing is often a symptom of a failed diode, in the rectifier pack, or brushes, in the alternator. Replacement rectifier packs and brushes should be readily available.

 

Herb

[markw81]

5 hours ago, ozieagle said:

The battery light flashing is often a symptom of a failed diode, in the rectifier pack, or brushes, in the alternator. Replacement rectifier packs and brushes should be readily available.

 

Herb

I’ll end up getting a new alternator.  By the time I’ve replaced those 2 bits I’m probably around the cost of a new. 
 

only question now is I’m seeing 80A and 100A alternators.  The one in my car is 100A.   Is 80A ok for a stock standard car nothing optioned etc.