Hi TJ,
If you battery light is coming on, this is indicating that the system voltage is below threshold. This is normally the battery or the alternator. However, if both have been load tested then move onto these items.
1. Inspect the serpentine belt (replace if suspect) and the tensioner to make sure your alternator is not slipping due to insufficient tension.
2. What is the voltage on the B+ wire with the engine running? Large red one that probably has a bolt holding it on. Not the red wire going to the PCM. I know you said you have voltage on it but what is the number?
3. Check you battery terminals and wires for looseness and corrosion, including the ground for the battery negative. The I would suggest doing a resistance measurement on them. Basically, this is just unhooking the cable from both ends and measuring resistance from end to end. This is where you set your meter to ohms and it should be around.5 ohms.
4. Just run through your fuses with the engine running and make sure you don't have any blown fuses. This is unlikely but is easy enough to check and could drive us nuts if not checked.
Let me know what you find and we can go from there. Thanks
Jul 16, 2019 at 12:33 PM
