If your battery light stays on and there is 14V or more on the battery with the car running, it is most likely the mega fuse on the main fuse box under the hood.. I had the same problem where the car alternator was putting out the voltage but the battery light was on and that was the problem. You can usually locate the mega fuse on the OUTSIDE of the hood fuse box. It is connected to where the battery connects to the box. Google what one looks like it is not a normal looking fuse. Just so you know what you are looking for.
Hope this helps.
Bill
Check the wiring and connections to and from battery
Does the engine just die or does it die because of the battery draining? The PCM is what fields the alternator(turns it on). It can be bypassed. First you have to check and see if the alternator wire has power to it all the time,B+(at the plug).If it does , you have to add a relay to it from the ignition on. Then take the other wire and ground it. This may keep the check engine light on. Been to long since I have done one of these.
It did but has brand new battery and the alternator.been checked with multi meter.was running ok light gone off for a day or so, now its back up and not putting charge back in. Thanks
Same vehicle as above 2004 Pontiac Montana ? Voltage drop test battery + wire to back of alternator .
https://www.youtube.com/watch?v=EMS8On17...
The system voltage sense circuit receives B+ voltage that is Hot At All Times through the ALT/SENSE fuse in the underhood junction block. This voltage is used by the regulator as the reference for system voltage control.
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SOURCE: F350 2004 6.0 brand
The first thing I would do is remove the alternater and take it to an auto parts store and have them check it. If the alternater is working good, then check the belts are routed and have the right tension. Either of these can keep the battery from charging. It's very common that a rebuilt alternater isn't working properly. If all these things are correct, check the live wire to the alternater is live. If it isn't alive you have problems in the wiring and I would take it to a mechanic.
First, you can't and shouldn't test an alternator by disconnecting the battery cable while the engine is running. You run the risk of cooking the alternator and the computer. Thats how we used to test generators back in the last century.
Is the check engine light on when the engine is running ? Is the battery charge warning light on ?
There should be a fuseable link between the alternator and the battery that could keep the alternator from charging the battery.
The ignition module would have no effect on the charging system.
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