How to Replace Alternator 2004-07 Toyota Highlander L4 2-4L

Hi, I’m Mike from 1A Auto. We’ve been selling auto parts for over 30 years!

Open the hood. We have to pull the release inside the car. It's just inside right around your left knee on the driver's side. Need to release the secondary or safety release. Just kind of feel around for it. This one is right here. Squeeze up. Use a 10mm wrench to loosen this. So you're going to remove the negative terminal. This one's a little loose just from being rusty. If you needed to, you could use an adjustable wrench because that would probably fit better, and do the same thing. Loosen it. Once it's loose, I should be able to wiggle it to come free, and then you can just push it aside.

The alternator is located here at the front of the engine, right on the top. You need to remove the belt from the pulley before you can remove the alternator from the engine. Now we use the serpentine belt tool to loosen the tensioner. It's not spring-loaded. It's got a shock on it, and there's a 19mm like welded on or it's a nut part, a hex drive that's part of the tensioner. When you pull down on this, basically you just have to slowly compress it. It's like a shock that you can see. So you don't pull really fast and hard because you'll break the tab off on the tensioner. You just sort of pull gently and slowly, and you'll feel it compress, and the belt will get looser.

See how the belt's getting loose? And then you pull it off the pulley if you don't have access to a serpentine belt tool. Take this out of here. We can use a breaker bar with a 19mm socket. I'm using a 12-point to give me a little bit more range, or you can use a large ratchet so you can have more movement. It's going to be a little bit trickier to get down here, so I'm going to feed the breaker bar with the socket down in there.

We've got like a bracket here, and there's this brake line that comes out, and you just kind of have to be careful to not bend them too much. You're going to do the same exact same—just reach in here and gently pull it, and it will compress. I'm going to push this out of the way a little bit. So you're pulling to the front of the engine. I'm going to carefully put a pipe over the end of this wrench over the end of this breaker bar to give me some more leverage and then just gently pull down and compress the tensioner. I see the belt releasing. I think that's as far as it's going to go. Reach down and lock it right off the pulley. I'm just going to lay it right there.

I'll let the tensioner back out. I'll leave that on there just like that and change the alternator. You need to unbolt the positive cable that goes to the alternator. It should be under a rubber cap. Just lift it up with your fingers. I'm just going to spray some rust penetrant on it. It looks a little corroded. I'm going to use a 10mm socket extension and ratchet to remove it, and then we'll lift it right up. Take the nut off. This harness right here should be zip-tied to this metal bracket. The zip-tie is broken, so it's loose. And on our alternator, I can remove it with this bracket attached because it's not attached to anything else; however, if your harness is zip-tied to it still, you're going to need to remove this bracket before you take the alternator out, so just spray some rust penetrant on here.

A 10mm bolt is going into the aluminum alternator. That broke free pretty easily. I'll just unbolt it and pull it out of the way. Otherwise, it would stay zip-tied to this harness, but on ours, since it's already broken, I'm just going to take it out. You can actually see how it works here if you wanted to unclip it. If you wanted to unclip this while it was still in the car, I'd spray some rust penetrant in here because this bracket's kind of rusty.

Take a flat-bladed screwdriver. Open up the tab, and then this should slide off, but again, it's pretty rusty, and it might be stuck. Worst case, I'd just unbolt it and leave it. Not a big deal. You don't really need it. We can put another zip-tie around it from the outside. I'm not going to worry about it.

Then disconnect the electrical connector. There's a lock on this side. Push in on the rubber boot. Pull straight off, so you're actually pushing in on this lock to open it up. The harness connects down to this bracket here, so I'm going to pop. By pushing up on the lock tab, I'm going to pop this harness mount out. This one's kind of worn out, and I think one of the tabs is broken. It's got a spring tab on one side, and a spring tab on the other side. Yeah, it looks like it's broken. You could come in from this side and squeeze these two together with needle-nose pliers, or try to do it with your fingers and it should come out of this opening.

There's another harness mount that's right here on the metal bracket, so to unlock this, I'm going to use a flat-bladed screwdriver and kind of open up the tab and then pop this open. So I've actually pushed open the lock tab. I'm going to try to just walk it off the metal. So I didn't unlock it from here. I just unlocked from the bottom, and then walked it off the mount. So now all the wiring is loose from the alternator. We can start to unbolt it.

There are two bolts holding on the alternator. There's one up here on top. It's got a 14mm head on it. There's a smaller one down here kind of underneath the pulley. It's hard to see. Let's start with the one on the top. Using a 14mm box wrench, I'm going to loosen it up. Now switch to a ratcheting wrench. You could also use a 14mm socket and a ratchet.

Before I take this bolt out completely. I'm going to go and loosen this bottom one now. So the bolt underneath is 12mm box wrench. I just have to reach down, and you kind of do it blind. You just find it. Kind of directly below the pulley. Loosen it up. Now that I've got it loose. I'm going to use a 12mm ratcheting wrench to help get it out quicker. All right, now that we got it loose, just pull it right out with my fingers.

It's a pretty long bolt. Starting to get this one loose. Start to turn by hand. Here it comes. This long bolt. All right, now we just have to work the alternator off the bracket. So just kind of grab it both sides and just wiggle it back and forth, and it should slide right off. I may need to pry it. I'm going to use a pry bar and just gently push against the block against the alternator and just kind of wiggle it back and forth at the same time. There it is.

Now I just have to take it out of the engine compartment. Careful of the harnesses. Let's see here. A little tricky to push them out of the way. Kind of guide it up and out. And there's our old alternator.

Here's our old alternator from our vehicle. This is our brand new one from 1AAuto.com. It does not have a core charge. It is brand new. You don't have to send it back. It came with a new nut for the positive terminal. The electrical connector is exactly the same. It has the same mounts for the top, and I'll spin it around. Same mount on the bottom. It has a new bracket for the wiring harness. Same amount of ribs on the pulley, so this will work great and fit great in our vehicle.

Now that it's removed, you can see where the lower bolt was. Take our new alternator. Get it into position. Start by lining up the top first. Slides in nicely. Take the top bolts.

Reinstall it. You may need to move the alternator around to line it up and just thread it in by hand. I've got the top bolt threaded in pretty much all the way by hand. I don't want to tighten it yet because I want to be able to move the alternator around. I'm going to take our lower bolt, and you just kind of have to feel around and line it up. Actually, it's going to go through the ear that's sticking out of the block, and then into the alternator.

The alternator is the part that's threaded. I'm going to tighten up the lower bolt. It's a very small bolt. The torque is 15 foot-pounds, which can basically be hand tight so I'm just going to snug it up, and when I feel it stop and get tight, there, and I'll give it just a tad bit more. That should be good.

I'm going to use a ratcheting wrench to snug the top bolt up. Since I can get a torque wrench in the top bolt, I'm going to use the 14mm socket on here, and the torque is 38 foot-pounds. I'm going to clip the harnesses back onto this bracket, so I'll take this one, and it should slide back on at the top just like that. It'll click into place. Snap the bottom one back on. Clip that one in. Plug the electrical connector back in. It's keyed. It will only go on one way.

That'll click when it's in place. Now we need to attach the positive cable. So this got spun around. I'm going to push the cover down to remove the nut that's on here. This will sit right over it. Install the nut. Take our 10mm socket and ratchet. Just tighten it down. It's about seven foot-pounds.

We want to be careful not to break it, so once you feel it get tight, go a little bit more and that should be good. So then slide the rubber cover back over it. That has positive power when the car is running. You don't want that to ground out. That's why that cover is there. Just going to take this broken zip tie out of here. Not going to worry about that. Your vehicle was equipped with this bracket and it's still attached to the harness, now you can bolt it back to the alternator.

It doesn't have to be super tight. Once you feel it get tight, go a little bit more, and then stop. Since our clip is broken, I'll use a cable tie and just attach this harness back down. Then we'll clip off the excess.

Now it's time to put the belt back on, but that was way too easy, so this belt slipped off one of the other pulleys, so I'm going to have to make sure that it's on all the correct pulleys. The belt is lined up on the pulleys. Put our bar back on here, and then gently compress the tensioner again.

It feels like it's bottomed out. So I'll pull tight on the belt. Slide it on to the alternator pulley. Pull the pipe off.

Release the tensioner slowly to let the tension come back. It won't spring back because it's like a shock. It comes out a little slower. And the belt is on there perfectly. Reconnect the negative terminal. Tighten it down.

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