Alternator problems??

[higgs1]

Hi
I think I have alternator problems as my battery keeps going flat. Its a brand new battery.

Vehicle details are as follows

Toyota Corolla 1.4 VVT-i T3 5-Door 2005

from what i can tell the alternator has an external voltage regulator. I am posting photos. Can someone tell me which is the positive terminal and negative terminal on the alternator. Also would i be able to replace only the voltage regulator is its faulty? I have bought an battery/alternator testing kit from screwfix which i will use to diagnose the alternator once i can determine the above. The leads have to be connected to the +ve and -ve terminals on the alternator whilst the engine is ran at around 2000rpm.
Any advice would be useful. Taking to a garage will be the next step but since I cant trust any garage to give me the most cost effective solution I need to do some research prior to the garage visit.
In general the car is in immaculate condition with only 25K on the clock.
Thanks in advance.
regards
Higgs

 

[Burnerman]

The alternators output terminal is the one on the right, with the thick cable. The others are the battery input and charging warning lights. The output is positive, the negative is the engine and bodyshell.
Most alternators have an integral voltage regulator and rectifier, but I can't comment on yours.
To test the alternator in a basic way, connect a multimeter across the battery terminals.
With the engine running above 1000 rpm you should see around 14.4 volts.....turn the lights and heated rear screen on and the voltage shouldn't drop below 14.
A faulty alternator can cause the battery to go flat due to rectifier failure. To test that, disconnect the alternator and see if the battery holds it's charge.....even disconnecting the battery terminals should give you some sort of indication.
John

 

[DaveHerns]

Is it your photos or is everything covered in oil? Oil may have got on to the brushes etc. Cleaning it with solvent eg brake cleaner may help.

 

[higgs1]

Hi Dave
You'll have to help me out here i'm clueless when it comes to car internals pretty much aside from the basics i suppose. When you say brushes what are those? and where are they? inside the alternator body?

 

[Peter.N.]

The brushes are internal to the alternator. Check the voltage across the battery with the engine running as per Johns post, if its much less than 14.4 volts the alternator will be faulty, either get someone to fit a new one or check the system or have a go at it yourself if you feel confident.

Peter

 

[higgs1]

Hi John
I tested using a multimeter the voltage did not even go up to 14V when the car engine was running. Which wire do I disconnect for the battery to be disconnected from the alternator?

 

[Burnerman]

Its the larger, heavy duty wire - but great care is needed as its directly connected to the battery!
It would seem you need an exchange alternator, and a motor factor would be happy to supply. Some have contacts to have your original unit rebuilt.
John