The battery light on the dash is on all the time. Started after a massive coolant leak that sprayed coolant all over the engine bay. I have since replaced the water pump, coolant hoses and washed the engine bay of coolant residue (washed from the hose, not pressure washer).

The alternator was recently rebuilt. Still tests good. I have 13.8v with engine running. I removed the positive wire at the alternator and made sure the connection was clean and dry. I removed the computer wire at the alternator and made sure it was clean and dry.

The battery is newish. Tests good according to a load test. I have 12.6v at the battery, at the terminals under the hood and at the alternator.

Why else causes the battery light to come on?