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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 43863
Experience:  16 years experience
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Ford f150: 04 f50, not charging, new battery, new alt, signal

This answer was rated:

04 f50, not charging, new battery, new alt, signal to and from ecm but no output, problem vnished for 3 weeks, now back again, help!

Hi, I’m Chris. Welcome and thanks for asking your question!


What brand alternator did you install?

Do you own a digital volt meter so I can help you diagnose this?


Customer: replied 4 years ago.
Reman, motorcraft by worldwide, factory alt which was in truck @ time problem started was bench tested and is good. Yes, I own a meter.

When testing voltage at the battery with not electrical loads on and the truck running what voltage are you getting?


With loads like the headlights, wipers, blower on what is the voltage now?


Customer: replied 4 years ago.
11.4 and drops......this has been tested by the electrical mechanic which ford sent me to, killed 1 battery with orig alt, swapped battery, same issue, swapped alt, same issue then went away, now same issue. Have taken new alt out getting ready to reinstall old alt. Have you had this issue before? Seen it before? Know you need to ask basic questions, but looking for some guidance, don't want to keep swapping alts and batteries.

Yes I have ran into quite a few times where as it came down to a faulty PCM or wiring issue or alternator. no particular failure seems common. You need to run some testing on the wires using the below test, starting with section B.

Also if needed here is the wire diagram.


If you get held up on any of the tests, just let me know and I will help you through it. I feel your going to find this to be the PCM since it has been checked out already and they seem to be avoiding mentioning the computer controlled charging system.





Thanks for asking your question. Your helping me pay my bills, and I

am hopefully helping you lower your repair bill or at least informing

you of the repair needed prior to getting it fixed.


You are about to see our rating system. The rating is how I am paid.

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I am only paid once you rate OK or GOOD or EXCELLENT SERVICE.


Please if you need to follow up, only press REPLY TO EXPERT.

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Thanks Chris

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