Auto Repair Articles

2003 Ford Excursion 4×4 6.0 Diesel keeps eating voltage regulators/alternators. Two brand new batteries charge on the charger and hold a charge. (I do have a 350ma parasitic draw while the truck is “sleeping.”) I even purchased a 200 amper from DB Electrical and installed an additional 0-gauge wire from the alternator to the battery. Checked the two alternator leads and soldered extra wire to relieve stress on the connector. No changes. At idle, the regulator side of the wire shows 11.6V. The batteries are barely charging at 11.88V. at 1K-RPM the battery voltage goes up to ~12.5. At 1.5K-RPM and above I get 13.89V maximum, sustained unless the RPM drops. This is repeatable.

Answer:

Sounds to me like you have a large load occurring with the engine running.Possible glow plugs staying on or FICM not coming out of injector preheat stage.I would suggest getting the load tested while engine running with a shunt type charging system tester and see how many amps are being pulled.If it has over 20 – 30 amp consistent load then you will need to determine what is causing the excessive load.A ford ids scanner will be needed to determine if ficm and gpc is operating normally.

How can I tell if My Car’s alternator is charging ?

There are a couple of ways you can do this. One is by using a multi-meter set to DC Volts. If the meter shows less than 13 Volts it is not charging(this is done with the engine running). Another indication is if the icon on the dash that looks like a battery illuminates then the alternator is not charging. Typically the alternator will produce 13.5 to 14.7 volts. If it does not you will need to replace the alternator. Make sure to check this after installation.

Directions for Testing with a multi-meter