Voltage gauge reads really low has replace.

Use a digital multimeter and double-check the voltage reading. Could be issue with wiring circuit, somewhere? Are there any charging system trouble codes? You may be able to check mil codes. I'll check.

Yes, you can check mil codes. You turn the key just till the dash lites come on, no further. Cycle the key, on--off, on--off, on. Then the mil on the dash starts flashing, you count the flashes to get the codes. Your looking for 2 digit codes.