Alternator Replacement – Toyota & Lexus V6

Here’s how to diagnose and replace an alternator on a longitudinally mounted Toyota or Lexus V6 engine.

The alternator is responsible for charging the battery in a vehicle’s electrical system. The battery powers up all the electronics, and most importantly, fires the spark across each spark plug to keep the engine running.

Typical symptoms of a failing alternator include, the battery light illuminating on the dashboard, consistently low battery voltage at startup, the battery voltage reading below 14.2V at idle or 13.8V under load, a burning smell or whirring sound near or around the alternator, flaky or intermittent electrical system operation (lights, instruments, radio, HVAC, accessories) or the loss of electric power steering.

In this video, a quick diagnostics using a multimeter is performed on a 2007 Lexus GS350 with a failing alternator and battery. The procedure to remove the alternator is then demonstrated.

Starting with removing the engine covers, the coolant jug and air intake duct are removed to gain access to the front of the engine. The accessory belt is removed, followed by two 14mm mounting bolts that hold the alternator to the engine block.

The final nut sits on a stud in the engine block and holds the back of the alternator through a bracket to the engine block, underneath the exhaust manifold. This nut is the most tricky part of the job, as it is not visible from above, so a camera or mirror must be used to locate the nut.

Access is generally tight along side the alternator against a wiring harness, the ECU (fender side), and the AC compressor down below. The manual calls for removal of the AC compressor first, however that it is not necessary, as the alternator can be maneuvered around the AC lines carefully.

Tools required include a 3/8″ ratchet, 1″ and 3″ extensions, various sockets (10mm, 12mm, 14mm), a 10mm wrench (ratcheting type works best), breaker bar, and an internal torx socket to transfer the alternator stud.

For this replacement, a Gates alternator belt, Remy re-manufactured alternator and Motomaster Eliminator battery were used as replacement parts.

This DIY tutorial is applicable to the Lexus IS250, IS350, IS300, GS350, GS300, GS450h, but will be similar for Toyota Tacoma, 4Runner, Crown, Mark X, FJ Cruiser and Hilux.

Check out the speedkar99 Facebook page:
https://www.facebook.com/speedkar9/

Follow me on Instagram:
https://www.instagram.com/speedkar9/

Subscribe for more videos just like this:
https://www.youtube.com/subscription_center?add_user=speedkar99