This is just from personal experience as my car eats alternators every summer. Living in Vegas with 110+ degree heat in the summer kills my car. Here's what happened when my alternator went bad:
Mid Summer time 100+ degree weather and I am driving home from school. My stereo turns off, followed by my AC, then my clock turns off, lastly my RMP gauge dropped down to zero while I was going 45 MPH (so it was just the gauge not my actual RPMs) Later that night after I am freaking out that I broke my car it got harder and harder to start. My battery kept dying and when I would try to start the car when I turned the key there was like a million clicking sounds. I took it into the dealer and sure enough it was my alternator.
Signs to look for:
- Stereo Turns off
- RPM gauge drops down low or all the way to zero while driving or idling
- Electronics in the car turn off
- Clicking noise when you turn the key
- The car wont start and jumping it doesn't work
If you notice any of these signs or symptoms call your dealer immediately and schedule an appointment so hopefully you are still able to drive the car there and not have to pay to get it towed in. If you are close to the dealer I would recommend driving straight there if they are open just in case the car wont start again if you turn it off.