* Alternator: This is the most probable cause. The alternator recharges the battery while the engine is running. A failing alternator might intermittently stop producing power, leading to complete electrical failure as the battery drains. Symptoms often include dimming headlights or other electrical components *before* complete power loss. Get your alternator tested at an auto parts store – many offer free testing.
* Battery Cables and Connections: Corrosion on the battery terminals, loose connections at the battery or alternator, or damaged wiring can significantly impede electrical flow. Clean the battery terminals with a wire brush and baking soda and water solution, and inspect all connections for tightness and damage.
* Battery: Even if the alternator is working, a weak or failing battery might not hold enough charge to power everything, especially under load (like using the headlights, radio, etc.). Have your battery tested for its ability to hold a charge and its cranking amps.
* Voltage Regulator (part of the alternator in most cases): The voltage regulator controls the alternator's output. A faulty regulator can cause the alternator to overcharge or undercharge, eventually leading to power loss. Often, a bad voltage regulator manifests as problems with the alternator's output.
* Ignition Switch: A failing ignition switch can interrupt power to various systems, including the charging system. This is less common than alternator problems but worth considering if other checks come up empty.
* Wiring harness: Damage to the main wiring harness, particularly near the alternator or battery, can cause intermittent power loss. This often involves chafing or rodent damage. This is harder to diagnose and may require a professional mechanic.
* Fuses and Relays: While less likely to cause a *complete* power loss while driving, a blown fuse or a failing relay in the charging circuit could contribute. Check your fuse box under the hood and the interior fuse panel.
Troubleshooting Steps:
1. Check the Battery Terminals: Clean them thoroughly. This is the easiest and quickest check and often solves the problem.
2. Get the Alternator Tested: This is the most important step. A failing alternator is the likely culprit.
3. Test the Battery: Check its charge and cranking amps.
4. Inspect Wiring: Look for any obvious damage to wiring, especially near the battery and alternator.
5. Check Fuses and Relays: If you've ruled out the above, check the fuses and relays related to the charging system (consult your owner's manual).
If you're not comfortable performing these checks yourself, take your Taurus to a mechanic or auto parts store for diagnosis. Driving with intermittent electrical power loss is dangerous, as it can lead to loss of steering, braking, or lighting.
