- 1). Open the hood of your 2003 Tundra. Disconnect the battery terminal cables by using a wrench to loosen the terminal nut.
- 2). Locate the alternator at the top of the engine on the driver's side. Disconnect the wires from the alternator by removing the nuts with a wrench. Unplug the wiring harness by squeezing the clip and pulling the harness out gently by hand.
- 3). Loosen the pivot bolt on the alternator with a socket and ratchet. Push the pivot bolt aside so you can pull off the alternator belt. Finish removing the alternator bolts with the socket and ratchet. Pull the alternator away from the bracket and out of the engine compartment.
- 4). Put the new alternator in place, and loosely install the bolts. Put the alternator belt on. Pull the alternator across until the belt tightens. Tighten the pivot bolt with a socket and ratchet. Tighten the other bolts with the socket and ratchet.
- 5). Reconnect the wires to the alternator. Tighten the nuts with a wrench. Plug the wiring harness into the alternator. Reconnect the battery terminal, and tighten the terminal nut with a wrench.
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