Alt new battery new no charging can i energize the alt i believe the ecu is faulty

Did you test the new alternator before putting it in. May be bad. Once you put it in turn the key and it self energizes unlike the older cars like vw. So if you forgot a wire or a plug to the alternator if it's good. Once the battery is connected it should be all set. So if that's not the problem you have to start looking for bad connections or melted wire and shorted a online fuse. Check your fuse box for any bad fuses.

Some vehicles are fitted with a smart charging system that is designed to prevent the alternator charging during acceleration to free a few horsepower to help.

My experience of these is very limited but there is an ECU that controls them and the battery, charging or ignition light using information from the engine management system.
The alternator generally has an extra plug with about four or five wires which when disconnected render the alternator a standard machine sensed type.

Japanese vehicles used separate voltage regulators longer than most types. You either need experience or a wiring diagram for good fault diagnosis but mostly it is unnecessary to check the charging current of an alternator which bears little significance unless being tested with a graduated load or adjustable carbon pile.

The current output of a healthy alternator is dependent on the terminal voltage of the battery which in turn is dependent on the electrical load placed upon it. Switching on the lights should lower the voltage and increase the alternator output. If the battery is particularly good the voltage won't fall very much and the current won't increase as much as expected...

Measuring the battery voltage with the engine running at about 2000/2500 rpm is sufficient for most purposes. With nothing switched on and a fully charged battery it should be around 14.5 volts and with everything switched on (lights, HRW, heater fan, etc.) a healthy alternator should continue to maintain a voltage above that of a healthy fully charged battery (13.2 volts).

If the voltage isn't maintained on load the charging system, probably the alternator, is faulty and should be independently tested.

Could be the circuit from the key that tells the alternator to energize.
You may have a 10amp fuse marked GEN that could be blown, and there could be a problem with the body or engine computer which controls the internal voltage regulator. You may need a shop manual to get the test procedures.

could be a fuse in the circuit blown, bad wire , bad earth (ground) , faulty regulator if it is not in the back of the alternator

Check your grounding strap from the frame to the block if ti is not grounding or it is not in good shape it will not charge the battery

at the alternantor you should have a small hot wire from ignition call the alternator energize wire, this wire has to be hot to tell the alternator to charge. run a hot wire to alt and check charging.

if you have the 2.0L non-turbo engine(420a) the voltage is regulated by the PCM(engine ecu). there is no voltage regulator in the alternator.

change your alternater

If you have changed the alternator and regulator, about all that could be left would either be a short circuit that is draining current away, or a bad ignition warning light bulb. That is because the power to energize the field of the alternator, comes through this dash bulb.

try putting your vehicle on a diagnostic check although you have changed the alternator the ECU ( car computer ) may still think that the alternator is still faulty a diagnostic check will cure your problem by clearing the fault codes on your ECU

dean