NEW BATTERY AND ALTERNATOR STILL NOT CHARGING HELP!

Hey so I have a 2000 Tacoma 3.4l and everything was running fine until about 4 days ago and It stalled out and died on me in the middle of the road. I took the alternator and battery to autozone so they could test it, battery was trash obviously but the alternator was perfect, (the previous owner put it in right before I purchased it) I’ve put everything back the way it needs to be(new battery) but when I turn the truck on, the voltage doesn’t move it stays at 12.4 and it goes doesn’t move when I rev it, I need to know if I’ll be able to even take this thing to work. I don’t have many options any help is great. Thanks!

 

I would invest is a cheap multi meter and spend an hour learning how to use it. With the engine running check the voltage right off of the alternator. You should be anywhere above 13 volts and more like 14 volts. If you have that voltage then check at the battery while still running. If you have battery voltage of 12.6 or below you have a bad connection or fuse. You should have the same voltage off the alternator directly as you do at the battery while the engine is running.

 

Are the battery terminal studs and clamps clean? Mine got gunked up and it was enough to break the circuit in my old 1st gen once.

 

I have a decent multi meter and for the past couple days I’ve been testing a bunch of stuff, the connection between the alternator bolt the case itself etc.. and it’s been 12.4-12.5 when it’s on and off, I’ve wire brushed down all the connectors and I’ve been able to rule out that it’s a wiring issue. I will prob take a new look at it a bit later.

 

Might be a bad alternator.

 

That’s the thing, I took it to autozone they tested it 3 times and they said it was perfectly fine passed everything, looks brand new as well.

 

Is the charge light on??

Make sure the 3 wire plug is not corroded

If things check out at Autozone with the Alternator it is either battery terminals cables or the wire from the B terminal of the alternator or the 3 wire plug poor main ground.

Battery positive to Alternator case reading in volts.

 

I’m about to go out and take a look at the truck once again, Thanks for the advice! I really do appreciate it, I’ll update you if that works!

 

Check the battery leads for continuity. A perfectly good 'looking' lead can be compromised inside, interrupting the circuit. Especially on an older vehicle.

 

Yeah I did a couple test with the continuity and I made sure nothing was connected where it shouldn’t be so I have everything squared up but it’s still been acting up.

 

Just FYI all my Battery cables and terminals have been upgraded.

 

I got one new terminal a while back, that is a good possibility the other one is trash, I’ll be taking a look at that

 

If you can take some pictures always helps.

 

Start truck, use jumper cables or use scrap wire to connect alternator directly from 'alternator positive out' to battery positive. If starts charging, there's broken wire or fuse in the charging circuit somewhere in the truck. Perfectly fine to wire it from alt+ to battery+.

 

What’s your voltage reading at the battery with truck running? It should be at least 14 volts. If not the alternator is junk. The guys at Autozone aren’t exactly techs. Unless a rodent got into something I bet you lunch at TacoBell the alternator is nfg. (you did remember to put the belt on, right?) Jk

 

That really sounds like a bad alternator. I can’t believe autozone said the alternator is fine with that voltage. You’re getting nothing from the alternator. I would also charge your battery ASAP to avoid suffocation of your new battery.

 

If we are sure the alternator is good, then
It sounds as if the Alternator isn’t even turning on?
I’d check for power to the IGN wire at the alternator with the key on.

If you want to know, how Toyota Charging systems work, look here.
http://wilbo666.pbworks.com/w/page/39441708/Toyota Alternators

 

Who can say we can only work with the data supplied.

If 3 different people at the auto zone place say things are good.

Really you would think they would tend to go the other way saying your alternator is no longer alternating time for a time one.

Then sell you a reman one that might not work better then the one it replaced that was a Sunday Adventure I don`t want to ever repeat.

 

I suspect that the alternator isn't grounded sufficiently to the motor or the motor to the chassis.

 

make sure you have +12 on the exciter wire going to the alternator with the key on. Check your main alternator fuse in the distribution block.