Q: ABS, fuel, and temperature gauge lights on when start car

Hello. I think that you should have your alternator retested by a different mechanic. The alternator cannot possibly be tested correctly with a dead battery. If the vehicle is not running, the alternator will not do anything. If the battery was dead, this would have prevented the vehicle from running. Therefore, the alternator is still a possibility.

If a new battery was installed and the issue was resolved for a couple of days, this would be another indication that the alternator may be failing because the fully charged battery enabled the vehicle to perform properly for a short period of time. Now that the new battery has been drained due to the alternators lack of charging ability, you are now having the same symptoms as before. If you want to have this problem resolved, a certified professional from YourMechanic can come to your home or office to test the dead battery and diagnose the ABS Light problem to see what repairs should be done. If the alternator tests bad, I would recommend having it replaced.