Alternator Dead @ 78000 - Replacement

[RSPEC429]

Figured I'd share with you all that my alternator died with 78000 miles on the clock. I was on a 5 hour road trip and it broke down 2 hours in to the trip and nearly stranded me. It gave zero warnings before it started dying out. Luckily, I was able to limp into a dealership. Being that I was two hours from home, had to continue on to my destination, and the car wasn't able to go any further, I had to have it repaired at that dealership. If anyone is curious, the alternator was $400 and labor was another $300. It's a shame it had to break down on me away from home, otherwise I could have easily done it myself.

 

[kn5owa]

Sometimes a bad battery can cause the alternator to fail

Might want to run a load test on the battery

 

[RSPEC429]

The battery was replaced in July with an Interstate battery. Dealership said it was bad, but I had it retested elsewhere and it checked out okay. It still has warranty on it so if it is bad, it's no big deal.

 

[kn5owa]

Its a big deal if the battery caused the alternator to fail, like maybe if it had a shorted cell.

 

[RSPEC429]

I could easily say the bad alternator ruined the battery instead of the other way around. I was driving for two hours on the highway so if the alternator wasn't charging like it was supposed to, I drove about 140 miles on battery alone and/or a reduced charging rate. Regardless, I'm going to have the battery checked out again just in case. So far the car has been driving fine.

 

[dougmcp]

With a shorted cell in the battery, the car would never start but a dead cell could cause the alternator to work overtime and may have led to it's failure. Driving for an extended time on the battery alone shouldn't hurt it much but it will test low/bad until you either recharge it or drive quite awhile to bring it back up to full charge. Checking the voltage of the battery is probably all you need to do at this point 12.8v is a full charge while something in the neighborhood of 12.1 is suspect and you will need a load test.
Here is a chart for % of charge vs voltage for your perusal:

 

[RSPEC429]

Thanks for the chart doug. I really don't know if the dealer recharged it before testing it so they may have just pulled it out, checked the voltage and said it was bad. Ran out of time today to have it checked so I'll have to do it tomorrow.