Alternator Testing and Replacement
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02 Removal and Installation
- Disconnect the negative terminal from the battery
- To give yourself some space and keep your sanity, remove the engine bay side cover. Itís 3 exposed 10mm bolts and will make the rest of this a lot easier.
- Loosen the drive belt.
- Pull the drive belt off the pulley of the alternator.The wiring will tend to pull the alternator rearwards so you may have to push the alternator forwards as you pull the belt off the pulley. The belt can just be dropped and left to hang there until we re-install.
- Remove Adjustment LOCK bolt, adjustment bracket and pivot bolt. The adjustment bracket and lock bolt are easy. 12mm for all bolts; one LOCK bolt and the two bracket bolts just inward of the adjustment bolt. Remove this entirely from the bay to give yourself a chance at removing the alternator. Finally, remove the pivot bolt. This is hard to reach. 14mm head size, located under and forwards of the alternator pulley. This bolt should pull out and clear underneath the engine bay wall. Thereís not much space to rotate the bolt so a ratcheting wrench is nearly a must here.
- Pull the alternator out of the lower pivot bracket.Be CAREFUL not to pull hard on the electrical wires. If youíve got real weak wrists you should disconnect these connections before pulling the alternator out of the pivot bracket. The alternator is heavy and the connections are difficult to remove. The main cable is bolted on with a 10mm nut. The other connector just pulls out after pressing the unlocking tab.
- Remove the alternator from the bay. This can be a bit of a puzzle. The alternatorís shape only allows it to come out in a couple orientations. Youíll need to squeeze it through the gap shown below in a similar orientation.
The First step of removal, as with most any electrical process, is the disconnection of the battery.
Tools: 10mm wrench/socket
Now come around to the engine bay. I think this is easiest from the top, although some steps could be performed from underneath the car.
Tools: 10mm wrench/socket
-Loosen PIVOT BOLT on bottom of alternator. This is a pain to reach. A closed or open end wrench should reach.
Tools: 14mm wrench
-Loosen Adjusting LOCK bolt. Only a few turns are needed to loosen the belt, but you can remove it entirely if youíd like as it will have to come off later.
Tools: 12mm wrench
-Loosen adjusting bolt. In my case (and I suspect yours), this bolt needed to be loosened a LOT. If youíve got an air/electric ratchet, you may save some time by using that here. You need to loosen this until the belt can slip off the pulley of the alternator.
Tools: 12mm socket
Tools: Optional pry bar
The order of the next couple steps is up to you. I found it easiest to wait to remove the electrical connections until the alternator was completely unbolted, but the Toyota service manual says to disconnect the wiring first. Of course, the Toyota manual also says the adjustment bracket doesnít need to come out to pull out the alternator and I canít see how that would ever be possible.
Tools: 12 wrench, 12mm socket, 14mm ratcheting wrench
Tools: 10mm wrench or socket
Alternator is now out. Take your beat up forearms and keep in mind youíre only halfway done on a job that on most cars is incredibly accessible and easy. Remember that the Mid Engine layout is worth the pain when youíre done. ;)