How do you replace alternator of Toyota Sienna?

Answer 1

<p>Replacing the alternator is a challenging but straightforward exercise for the novice car mechanic. Consider also replacing the alternator belt at the same time. This should be replaced every 60,000 miles. </p>

<p>The alternator is found on the left side (as you face it from the front) of the engine, toward the front. It is a small roundish silver-colored thing that seems to have a lot of ventilation holes in it. </p>

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Start by removing the cable from the negative terminal of the battery (the one without the red plastic cover). This is always the first step when working on any part of the electrical system. Use a 10mm socket to loosen the connector, and then slip it off the top. Tuck it out of the way so that it doesn't accidentally connect again. </li><li>

Remove the cable from the alternator. The cable is attached under a "boot" attached to the top. Slip the boot back, and use a 10mm socket to remove the attaching nut. Be sure not to drop it into the engine compartment, because you will never find it. After removing the screw and detaching the cable, remove the boot as well, so it doesn't fall off and get lost. </li><li>

Remove the wire harness from the alternator. This is a small plastic connector with many wires. There is a small spring clip on the side. Squeeze it and pull firmly. Tuck all the wires out of the way. </li><li>

Identify the three bolts holding on the alternator. The "top" bolt is on the top on the left side. The "bottom" is in on the bottom, in the same orientation, but hard to see. You may need to find it by feel. Third is the "adjuster" screw, which is near the bottom bolt, but sticking straight toward you, visible. Loosen all three bolts slightly (12mm for bottom and adjuster, 14mm for top)

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Now remove the adjuster screw completely with a 12mm socket. This is like the longest screw you have ever seen, and it takes a while to get it out.

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Remove the bottom bolt with a 12mm socket. There is a small "cube" that comes out with it, be sure not to drop it.

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Remove the top bolt with a 14mm socket. It looks like a long bolt, but it is only threaded a short way, and should pull right out after a while.

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Now wiggle the alternator loose. If it is stuck, you can bang it a little with a piece of wood and a mallet.

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Slip the belt off of the pulley on the alternator. Don't try to remove the belt entirely from the engine right now.

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Now you have to extract the alternator from the engine compartment. This can be more difficult than it looks, because you have to manipulate it around some wires and hoses. Gently flex the hoses as necessary to make room, but try not to break anything. You may also want to temporarily disconnect the right headlight wires if they get in the way.

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After the alternator is removed, remove the belt by unhooking it from the lower two pulleys.

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Now take a break, clean your hands, and relax. Turn the belt inside-out and inspect it. It should be free of cracks, tears, and missing spots. Get a new one if you need to. Do a sanity check on your new alternator. Make sure the connectors are all the same, the bolt holes are in the same place, and the belt fits on the pulley. Sometimes an after-market alternator will look a little different, but it should still fit.

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Hook the belt back on the two lower pulleys.

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Manipulate the new alternator into place. The part with two bolt holes is the top, one hole is on the bottom, and the electrical connections are in the front. While you are doing this, slip the belt onto the pulley, and make sure it's still wrapped around the lower pulleys.

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Put the top bolt in. The top bolt is the long one with only a small amount of threading on the end. You will need to wiggle the alternator to get the holes lined up. Tighten the bolt just a few turns to make sure it's in all the way, but do not tighten it all the way yet.

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Look at the "cube" you removed in step 5. There are two holes; one with threads, and one without. Put the bottom bolt through the hole _without_ threads, then try to screw it into the bottom hole on the alternator. You probably have to do this by feel. There is a slot that the screw goes through before actually entering the alternator hole. Tighten this bolt most of the way, but not fully tight, so that the "cube" can spin a little in place.

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Put the adjuster screw in. This goes through a slot, and then into the other hole in the "cube". Start tightening this screw; it will take a while.

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As you are tightening the adjuster, the belt will begin to tighten up. Check it regularly, and do not overtighten. Do not overtighten! The belt should not be violin-string tight, nor should it be limp and floppy. The belt is tightened when you can push it about 1/2 inch in the middle.

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When the belt is the correct tension, tighten the top and bottom bolts on the alternator fully.

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Reconnect the wire harness (it should snap right on). Slip the boot back onto the cable and connect it to the alternator with the small nut.

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Reconnect the negative cable on the battery.

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Now its time to test your work. Make sure all tools and stuff is removed from the engine compartment.

With a multimeter, check the voltage between the battery terminals. (Set the multimeter to the VDC or _V setting. If your multimeter has several sockets, the red probe should be connected to the "V" socket, and the black probe to the "COM" socket. Clip the black probe to the negative terminal of the battery, and touch the red probe to the positive terminal, under the plastic cover.) It should read between 12 and 13 volts.

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Start the car. Make sure the alternator (battery) light on the dashboard goes off.

With the engine running, turn on the headlights and the fan. Check the voltage between the battery terminals again. It should be between 13.5 and 14.5 volts.

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Celebrate by re-programming all your radio stations.

If you replaced the alternator belt, it needs to be retensioned after running the car for 15 minutes. Stop the engine, loosen the top and bottom alternator bolts, and tighten the adjuster bolt as before. Then retighten the top and bottom bolts.