Faulty Alternator?

[Sean Reynolds]

Hi gents,

I've currently got a problem with my Toyota Camry 2005 Altise (ACV36R),

When driving home the other day, I noticed that the power to my head unit would switch off, then back on.
Once the headlights were turned on, the radio cut out as well.

When I arrived home, and turned the car off, I was unable to start it again.
I checked and found that I had less than 10V across the battery terminals (which were extremely corroded). The battery is now 6 years old.

Given the age of the battery, I decided to replace it with a new battery, and clean the corrosion on the leads.

Now the car starts fine, but I'm not seeing an increase in voltage across the battery terminals when the car is running (even at 2000RPM). It's just slowly dropping, which is leading me to believe the alternator is damaged. However, there is no battery fault lamp indicator (the bulb is fine - lights up on startup).

I've done a diode test of the alternator. No issue found.

I've done a continuity check from the alternator to the positive post of the battery terminal. No issue found.

I've sourced an alternator for $250. Just wanted to get any other ideas here before I commit to purchasing it. The only reason I'm holding back from getting one, is that there is no battery warning lamp; which I would expect to see if there was a charging problem...

Appreciate any help.

Thanks

Sean

Edited June 11, 2017 by Sean Reynolds

[campbeam]

 I cannot recall whether I had a battery indicator come on but I expect it must have. The alternator on a previous partner's Corona stopped working and the car was running on the battery alone [did not know that at the time]. Headlights were quite dim when I finally got home. Removed the alternator and discovered that the brushes were quite worn but had got stuck. Easy fix so brushes able to make contact again.

[trentmeyer23]

What ia the charge voltage?

[Sean Reynolds]

I've realised when I start the car, I get 14.1V charge across the battery terminals.

Within a minute, it falls to 12.6V, and stays there (even if the engine is rev'd to 3000+ RPM).

 

[trentmeyer23]

Probably regulator/brush related.