2000 avalon electronics/ AC and windows not working after alternator replacement

Voltage is too low, should be around 14.2 to 14.7 volts running and around 13.2 engine off. Now if the battery was disconnected without hooking up a memory saver tool that plugs into the OBD 2 port then you have corrupted the computer programming. So you have more than one problem and it sounds like it is time to visit the dealer to get the programming fixed.

your saying that having the battery disconnected can corrupt my computer? That makes no sense to me. The battery has died in the past and all I had to do was put a new one in and enter commands to get my radio to work. By computer do you mean the ECU? Could I just replace that part?

No BCM, it contains all the programming for your accessories, like windows, AC, power seats etc. Not all system maybe effected but some might be. The computer also controls the charging system.

You should also check the fuses in the power distribution box under the hood, see if any if those fuses are blown.

ok.. so I may need a new BCM. Is that whats under my dash that I am plugging the reader into? How difficult is that to replace? Also, when checking the fuses under the hood. Are those the type that you cannot tell if they are blown and need to bypass or replace? or is there a way to visually see if they are bad? BTW I really appreciate you taking the time to help me.

That plug is the OBD 2 port, that will give you information on the engine management system, if you have a dealer quality scanner you can also read and program the BCM from that port, but those scanners cost a lot of money so only dealers have them. You may not need a BCM, just a reflash of the stock unit. The fuses in the power distribution box will be visually blown, but if one is just cracked you won’t see that, using a test meter helps.

Answer not posting

I get the BCM not letting the electronics work but would that also cause the new alternator to not be able to charge the battery?

As I don’t have a flow chart or wiring diagram of your vehicle I can’t tell if they ran the charge control through the BCM or the ECM, most use the ECM. Now when you first turn the key on but not start the engine do you see a charge or battery light? If you do that’s good if you don’t then that light needs to work as it is part of the exciter circuit for the charging system. Before you do anything else make sure you test all the fuses in the distribution box.

Answer still not posted

with key on position there is no light for the battery. The only lights that come on are for door ajar. none of the dash lights or the lights for the heating and air conditioning and radio come on. Not sure why I am not seeing answer in post but I see your response in email. thank you.

can i test the fuses in the power distribution box with my voltmeter?

Yes on volt meter. There should be a battery or alt light that turns on with the key, you might need a flashlight to see where it is.

There are many fuses. Most do not seem relevant. I checked the fuse that says " charging system", its only a 5 amp fuse but appears intact. I rechecked the connections on the alternator and made sure it is spinning properly. Inside the car still nothing. Sunroof, windows, all dash lights (except door ajar) do not light up with key on or when the car is running. The entire center console acts like the car is dead but I can hear the cd disc changer trying to free itself of a disc that has been trapped in it for a decade now. Oddly, I can use the power lock button on the door to unlock the car but it will not let me lock it.

This still sounds like a BCM glitch but you may have more problems. I think it's time to let a Toyota professional have a look at it. They may have to do a re-flash before they can do much else.