[JoshuaNaismith]

Hello,

I have a 2007 Toyota Rav 4 RHD 2.2L D4D that's not charging even after an alternator change + replacement battery

I bought the car last week and I fitted a trailer plug to it (All wiring was correct and had been inspected at either side to confirm that there was no shorts etc)

one day later I was driving on the motorway (freeway for you Americans ) the car cut out all the electronics wouldn't charge this was due to the alternator not charging the battery

The battery would go from 13V from a jump start and rapidly decrease in increments of .1V DC until the car cut off at roughly 8V DC....

The tension on the belt was acceptable and the battery was already new (confirmed this by fitting 3 other batteries from all my other cars)

So I removed the alternator took it to a repair shop and they've confirmed everything was working on it they even put it on a test bench to show it was working and charging okay

After refitting the alternator onto the car again I bypassed the + cable on the alternator to the + on the battery in case there was any breaks (even after doing a continuity test to ensure everything was fine I still bypassed the cable to be double sure) and double grounded everything temporarily from the body to engine back to the battery to ensure correct grounding

Still the same issue occurred after bypassing everything

After some inspection I checked the 4 pin plug that goes into the alternator

two of them have 12 VDC and the other 2 have no voltage at all is this correct and normal?

Is anyone clued on on the wiring of the 2007 RAV4 alternator 4 pin plug and what each cable does

Should the alternator still charge regardless if there's issues on the 4 pin section of the plug

 

[JoshuaNaismith]

Will also mention that the battery light is not on when ignition switch is turned on if this affects anything

 

[Dr. Dyno]

I haven't checked the schematics but as I recall the alternator needs to have enabling current via the light.

 

[Bigphil555]

@Dr. Dyno is correct, I have just looked at the wiring diagram.

The charging light is fed off the instrument panel junction box. There is a 7.5A fuse called Gauge 2. This should be hot at start or key in the on position. At the alternator connector this is the blue wire on pin4 - if you are handy with a DVOM, check the power there for system voltage (12V)

 

[TomKatt]

I'm not sure about the 2007 models, but at least starting around '09 the charging current is controlled by the ECU for fuel economy reasons - these aren't your old 1 wire charging system. The main power distribution to electrical loads flows throw a current sensing coil located in the main fuse box, and the ECU decides how much field current to send to the alternator to generate charging current.

It sounds like the 2 pins you found that have no voltage on them are likely the field winding supply... Without power going into the alternator field, you won't get charging current out. Also, bypassing the wiring to the battery with a direct connection might also bypass the current sensing coil, which could possibly cause the ECU to get confused and not "turn on" the alternator.

Certainly, the lack of the battery light turning on when you turn the key is a big clue - that should light even if nothing is running. I second Bigphil555's suggestion above.