Alternator question

Hi and thanks for using 2CarPros.

Yes, if the voltage regulator fails, the alternator can produce high voltage and damage wiring, components. However, the starter itself usually isn't an issue because the circuit to the starter isn't closed until the key is in the start position.

If you feel the alternator may be over charging, here is a simple test. First, check the battery voltage with everything off. It should be right around 12 volts. Start the engine. It should be around 14 volts. If it goes beyond 15, that is a concern.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

With that in mind, here is the real problem. The voltage regulator is an integral component within the power control module (PCM). If the regulator is bad, the PCM needs replaced. This component isn't cheap and unless you have specific equipment, it will need taken to someone to program for your vehicle.

Let me know specifically what has happened. I may be better able to answer your concerns.

Take care,
Joe

Thanks Joe for the quick response! Here is exactly what is happening:

Took car in for a battery light. Mechanic determined it was the alternator. Upon further diagnosis they said the starter is bad too and the alternator may have “spiked” and caused the issue with the starter. Replaced alternator, starter and battery. Now the remote start does not work, error on dash says hood ajar, it’s not. The horn sounds like a mouse and the airbag light is on. I took it back in for them to look into the issues and when they couldn’t figure it out. I left and noticed my headlights aren’t on but interior lights are on and the little light on my dash that says my lights are on is on as well.

OMG! I have no idea where to start with that one. What did they tell you? Are they offering to have it repaired at a different shop and they pay for the repairs? Without being there and considering the work that was done, I would start by checking if a ground has been disturbed. There are so many things happening, the one common thing that can cause these problems is a weak ground.

Do me a favor, just for the heck of it, do the alternator test I suggested. I want to know what is going on there. And no, the starter itself didn't get damaged by an over charge.

Let me know what you find.

Joe

PS: After thought. Does the check engine light stay on when the engine is running?