SureTrack Community Fix: This Bull Won’t Charge

Real Fixes from the SureTrackĀ® expert information resource are documented issues from actual shop repair orders and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is currently available free with the purchase of a current Snap-onĀ® diagnostic software version.

Chasing your tail on an issue can lead to a lot of frustration. SureTrack community member pdmason1492 had a Ford Taurus in their shop that wouldn’t charge the battery, They posed the question to the community, and with the help of fellow community member DAG1365 and others, they were able to resolve the issue quickly.

The following Real Fix summarizes the interaction between them in the community that led to the solution.

2003 Ford Taurus SEL 3.0L

Battery not charging, loose fuse.

Customer complains that car is not charging.

Diagnostic Steps Performed/Parts Replaced
Customer states that the battery goes dead. Tested alternator and found it’s not charging, no battery light except during key on, engine off. Charged and tested battery and found to be ok. Test alternator output, found none. Check B+ at alternator and found 12.5v. Replace d alternator with remanufactured unit. Still not charging. Had parts store test old alternator and they said it was bad. Replaced alternator again. Still not charging. Had store test previous remanufactured alternator and they said it was good. Scanned vehicle and no codes and no battery light. Using repair information, tested pin 3 and it has 12.3v. Backprobe pin 2 at alternator (Gen Com) key off 0.00v., KOEO 0.3V., KOER 0.00V. Backprobe pin 1 at alt. (Gen Mon) key off 0.00v., KOEO 0.5V., KOER 2.3V. All tests passed except last one (KOER, Should be 6v.) According to the diagnostic steps. Replaced PCM. Still not charging. What tests do I perform to reach an undisputed conclusion?

Best Answer from Community Member DAG1365
Is fuse good in central junction box? do you have same power at instrument cluster to light? Check pcm connector for any damage. Be sure no wiring is shorted to ground on those circuits. Have had problems with central junction box internally at times causing no voltage on circuits, Be sure main powers and grounds clean/tight.

I found the 175 amp fuse at fuse box was not clean and tight. Probably should have done a voltage drop test on the B+ circuit. I am so relieved. Thank you for your advice. Will use this avenue again.

Cleaned and tightened 175 amp fuse at fuse box. Alternator is now charging as it should. All tests within specifications.

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About the Author

Nick Taylor

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.