Replaced battery and alternator, battery still wont charge, now CE light is on

So during a 6 hour drive recently I had to replace my battery and alrernator, as both had quit on me. We got the van working for a bit, but I couldnt use my a/c and charge my phone at the same time or a bunch of lights on my dash would turn on and my van would basically die. Now, my battery is dead again, and i just had to jump my van because it wouldnt even turn over. Also my check engine light came on. Battery and alternator were from O’Reillys.

Duplicate post.

Its not a duplicate post. New issues have come up.

You’ll get advice about double checking the battery cables, making sure that the connections are clean and tight. Also advisable to use a multimeter to check that the battery reads over 13.5 volts or so when the engine is running. Checking the battery with the car off should yield a reading about 12.6 volts. If the voltage when running is not up to specs then the problem might be with the alternator. If the battery reads low with the engine off, then there could be problems with it. You don’t say why both had to be replaced at the same time. Was the old alternator not generating enough voltage? Was the old battery in need of replacement due to age?

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Another possibility—serpentine belt and tensioner need replacement. That or the AC compressor has failed and causing too much drag.

@jdmere offers good advice about measuring voltages to aid the diagnosis. My guess, nothing wrong w/original battery, original alternator failed or fuse blown, prevented battery charging. So why is it not working now? Either faulty replacement alternator, same faulty fuse , or some other wiring problem remains.

Re wiring problems, many years ago I had similar problem on my Corolla. Turned out the main charging wire, big and thick, from the alternator to the battery had broken at a splice deep inside the wiring harness. Battery apparently had sprung slight leak at top, and battery acid decanted down the + wire bundle until eventually it came to & ate up the splice. Re-soldering the splice with a heavy duty soldering iron did the trick. Gaining access to the splice, that part of the job wasn’t so easy.

I wonder if a fusible link or maxi fuse has blown