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2008 F250 W/ 6.4 Diesel, Battery light came on and my

2008 F250 W/ 6.4...

2008 F250 W/ 6.4 Diesel, Battery light came on and my scanner is saying the voltage is up to 15.9V. The batteries were 6 years old and tested bad so I replaced them. I am still having the same problem, should I just swap the alternator?

Mechanic's Assistant: Have you tested the battery? Have you tried testing the alternator?

The batteries are brand new, I have not tested the alternator

Mechanic's Assistant: Are you fixing your F250 yourself? What have you tried so far?

Yes fixing it myself. I honestly haven't looked into much testing yet, I got frustrated with it and quit driving it. I will take it to napa tomorrow and have them run an alternator test on it. The high voltage is what is bothering me, I've had plenty of alternators go bad but they usually just quit charging, not pump the voltage up to 16

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

The headlights blink when the voltage goes too high

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Answered in 1 minute by:
3/16/2018
George H.
George H., ASE Certified Technician
Category: Ford
Satisfied Customers: 19,278
Experience: ASE Master Tech 15+ Years
Verified

Hello I will help,

It probably is the regulator in the alternator but do you have a voltmeter to double check what the scanner is telling you?

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Customer reply replied 4 months ago
Ok, That is what I was figuring. I do have a volt meter to double check it, I just have not gotten to checking it yet.
Customer reply replied 4 months ago
would excessive voltage cause the headlights and cruise control to act up as well?

Yes it would, might affect the radio as well

George H.
George H., ASE Certified Technician
Category: Ford
Satisfied Customers: 19,278
Experience: ASE Master Tech 15+ Years
Verified
George H. and 87 other Ford Specialists are ready to help you
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Thank you, ***** ***** me know if you have questions in the future.

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Customer reply replied 4 months ago
No problem, Thanks for the help
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