Alright, what we got here today is a 2003 Ford wind star and what I'm going to be showing you is how to do with a battery on light that is still illuminated. Even after you do an alt and there changes, alt and there was rebuilt and reinstalled by our shop and then brought us because the light didn't go out. My very test of this vehicle actually has a bad regulator. I'm going to show you how to verify that the regular is doing what is supposed to be doing on a computer controlled six generation Ford charging system. First things first, start the vehicle up. As you can see right now, the only light on is the check engine but the battery light comes on and comes off as it wants to. There it is. As you can see it's on now. First thing we're going to do is we're going to go ahead and do a co-check. This time I'm using the genesis rather than the Bluetooth unit because I can get a better diagnostic on this one. Let's go into the Ford. It takes it a second. Let's use it. Oh, that was the generic module. Let's go into the engine control module. Now, the reason I'm showing you this is it has a lot of various problem codes but something stands out is there is a couple of charging system related codes and anytime you have a lot of random codes and you have a charging system issue, you need to take care of the charging system issue first. As you can see there's a lot of O2 codes and then this alternator code here is a P1246 and if we go out and go into the ABS system, we'll go down here to read codes. You can see all the ABS codes and a 1317 battery voltage high code. You can't know these are reliable codes. Anytime you have voltage just way above or way below it's supposed to be, it could create all kinds of problems inside the ECMs, the bi-control module, transmission control module, ABS control module. You can have all kinds of issues because voltage is fluctuating outside the computer's control. Let's find out what's going on with the charging system. As you can see, you got my voltmeter hooked up to the charging system and we show you we got about 14.2 volts which isn't too bad, it's about what you'd expect. We're going to hook up a clamp meter up to the cable going to the alt-narracy, what kind of load the system is under. This will have hooked up to this other voltmeter real quick. As you can see that the clamp meter is hooked to the voltmeter, read Z-roll, that's what you want, even just this to get it to Z-roll if you need to. We're going to clamp it around, the feed line, you see right now systems full about 19 amps, headlights or parking lights are on, so that's about an almost per-nomot, see what happens. As you can see you can see, the amp is coming down, we're about 16.3 amps, that's not too bad. Now, since we have a battery light on, this could be hard to do because it's getting dark, this could be if we'd put leaves to nice I wanted to do this before it was gone. All right, as you can see there is a three wire terminal here, three wires. The way they're split up is the first wire closest to the main battery terminal, should read, turn the scope on. This wire should read battery voltage, as you can see it does. So that means you have a good connection between this wire and the fuse box where it connects. The next wire is a signal send from the PCM to the Alt-There to control its voltage. This is another five volt square wave signal, and the computer changes the dwell on the signal to control how much the regulator should be attempting the charge system. So what we should see here, let's back out of this, and get into the lab scope mode. What we should see here is, like I said, a five volt signal, it's slowed down our time base. All right. And as you can see, we have a waveform. I have a pretty good one too. There it is. Nice and clean. The computer is trying to do something with the alternator. Now the way it knows if it's doing it right or not is it actually uses this last wire, the one closest to the front of the vehicle, as the field reference wire. This wire sends a signal back to the PCM that the PCM uses to determine how much it's affecting the field coils. Let's connect with that. And nothing on the meter. So let's go up to this great volt meter. And yeah, as you can see, there's no voltage on the field return line or the field reference line telling me that the regulator inside this alternator, even though it was rebuilt, is no good. If this regulator is either no good or the wrong one, that sometimes does happen. There are a couple of different regulators for these four or six generation alternators. If you get the wrong one, you will have all kinds of issues. So what's happening is the computer is sending a signal to control the alternator. The alternator is responding and charging the system. And actually at times it's overcharging the system. I've seen that the height goes high 16 volts earlier today. But the regulator is not recording back to the alternator what's going on. And since it's not going to report back to the computer until the computer what's going on, the computer is assuming that the charging system has failed. And some way it has turned on the light. And of course with system voltage being a rad it because the computer does not have complete control over it. That can cause other code issues. So I've this customer is coming to get this vehicle. They're returning it back to where they had the alternator rebuilt. They're going to have them take it back apart and recheck everything and have them fix the problem. Then they will clear the codes, drive the drive cycle and see what returns. If no codes return them that's the only problem. If I start troubleshooting all those codes it's most likely that they're not actually faults. They were generated faults by voltage problems inside the system. Alrighty that's pretty much it. Another thing to notice is of course your main terminal should always have your battery voltage on it of course. But that's it. Six generation alternator is a pretty simple. One wire going straight to the battery. One wire in the connector, the closest to the rear of the vehicle goes to the fuse box. If you have alternator it's not charging all, check that fuse. The second wire comes from the computer to control the regulator. The third wire comes from the regulator back to the computer to let the computer know what's going on. And I hope that was helpful.