Replacing an alternator can save you money. It is one of the simplest repairs you can do at home. With a few tools and about an hour you can swap it out yourself -- and keep your dough in your pocket where it belongs.
This guide provides a detailed walkthrough for replacing the alternator in your 2003 Ford Taurus, including considerations for high-output upgrades and necessary precautions.
Essential Preparations
First and most importantly: disconnect the battery. There may be several wires or just one wire on your alternator, but rest assured that one of them is hot. If you don't disconnect the battery, you're very likely to end up grounding a live wire during the process.
Step-by-Step Replacement Process
- Disconnect the Battery: Ensure the vehicle is safe to work on by disconnecting the negative terminal of the battery.
- Disconnect Wires: Now that the battery is out of the way disconnect the wire or wires from the back of the alternator.
- Remove the Belt: Every project has a tough spot, and this is the tough spot for alternator replacement: remove the belt from the pulley. Somewhere on your vehicle there is a tensioner pulley. You'll need to move it enough to slip the belt off the pulley. On some vehicles you'll find screw-type or rod-end type tensioners that apply tension by turning a bolt through threads to increase/decrease the length of a rod. In this case, just turn the bolt/rod-end with a wrench or socket until it releases enough tension to allow you to remove the belt.
- Remove the Alternator: Once the belt is off just remove whatever bolts connect the alternator to the bracket and you're good to go.
- Mount the new alternator.
- Reassemble: To complete the project just reverse the removal steps paying careful attention to belt routing and tensioning.
With the old alternator in your hand you're half way home. Examine the replacement unit before reassembly and make sure it will work for your application.
Upgrading to a High-Output Alternator
This is a direct fit high-output alternator for the 2002-2007 Ford Taurus 3.0L. This high-output alternator comes with a factory style plug so that your OEM plug will plug directly into the alternator.
Read also: Engine Details: 2003 Taurus
When Upgrading to a High-Output Alternator, it is required to upgrade your wiring with the Big 3 Wiring Upgrade Kit. It is recommended to use 1/0 100% copper wires for the upgrade.
Each of our high output alternators come with smaller overdrive pulley. This pulley is made to increase low RPM charging for maximum output. It is custom for the diameter of the overdrive to be less than your factor pulley, depending on the kind of vehicle you own. For this reason, unless otherwise specified, you will need at least a 1/2 inch shorter belt. You can purchase this from any auto parts store.
Our high output alternators come with an overdrive pulley. The pulley is designed to improve low RPM charging so that it yields maximally. Do not change this overdrive pulley out with a larger diameter pulley. When alternator pulley diameter is increased, the output amperage decreases.
Important Considerations: It is important to make sure that the small regulator plug that is located on the back of the alternator is well plugged in for the correct functionality. Do not forget to plug it in completely, try not to jam the plugs in backwards, and avoid pinching it in order not to create a short.
Connections and Grounding
Connections Of Frame/Body: Clean all metal surface of any paint or rust with a wire brush or die grinder. Use a conductive corrosion inhibitor available at any electrical parts supply store.
Read also: Ford Taurus 2003: Troubleshooting
Grounding (Uni-body frame warning): Many newer vehicles have “uni-body” or sheet metal frame structures with no traditional “full frame”. Because of seams and adhesive attached body components, additional steps may be required for proper chassis grounding. Choose the location on the sub-frame with the thickest metal possible.
Factory Plug: The factory harness can be plugged into the new regulator.
Self Excite Alternators: Self-exciting or better known as “one wire” alternators will have NO plug on the alternator, and the OEM alternator harness plug will be left disconnected. This type of alternator requires only the positive and negative battery cables to be connected to the alternator to function. These alternators are internally regulated and will turn themselves on and off with engines rotation and regulate their own charging voltage. For protection it is recommended to add an in line fuse to the positive wire. All factory connections need to remain connected.For protection it is recommended to add an in line fuse to the positive wire.
For some older vehicles, the factory style regulator is not available with the hairpin style alternator. This is why your high output alternator will come already “upgraded” with the 15 volt regulator. It will have an oval plug which requires splicing into the factory plug.
Warranty and Returns
Looking to return an item? All JS Alternators come with a 1 year warranty. Powder coat is non-refundable as it is custom powder coated per order. Original invoice or copy of original invoice must be included in order to receive warranty service. This warranty covers repairs to the JS Alternator only and does not include other parts on the vehicle. This warranty does not include any labor expenses for installation or uninstallation of the alternator.
Read also: Comprehensive Guide: 2006 Ford Taurus Catalytic Converter
All JS Alternators are custom built to order. New and unused standard alternators may be returned within 90 days of purchase but will be subject to a 10% restocking fee after full inspection. After 90 days from the purchase date have passed, all orders are non-refundable.
We offer lifetime warranty on alternator labor and a one year warranty on parts.
All orders are heavily wrapped for shipping with several layers of big bubble wrap and two layers of boxes along with a Fragile sticker on the box. If you have to ship your alternator back, please be sure you wrap it the same way to prevent further damage.
Shipping Information: We offer free shipping in the United States. Orders ship in approximately 3-5 business days, sometimes sooner. Many alternators are shipped the same day. Alternators that require a custom bracket can take 5-8 business days. If for some reason parts are on back order, we will notify you, but this is not common.
Troubleshooting
As promised to all our customers, our products are fully tested ensuring their outstanding performance before shipping. In our experience through the years, it is in many cases not the alternator itself. The reason could be one of two things: Either the plug is wired incorrectly or the computer is sensing the higher voltage and causing the battery light to come on even though the alternator is charging properly.
Additional Options
NOTE: If you require charging at a certain voltage setpoint, we offer a selection of different voltage regulators that you will need to purchase with the alternator for it to be installed. View our Regulator Options Here.
We currently offer a curated lineup of powder-coating colors displayed on this product page. These are the only finishes available at this time, although we’re always exploring new options for the future.
Hell, even if you bought the set of Cross Force wrenches for the job you'd still be hundreds ahead of the cost of what a shop would charge -- and you get some new tools out of it.