Originally Posted by Soccercop
Now, onto the reverse light switch.
I'd replace the alternator. If you're not confident doing it yourself-I wouldn't hesitate to take it to Pep Boys (as silly as that sounds). From what I've read-they gave me a solid price.
I have a contributed to a thread on this, its quite simple and likely the switch.
I had identical symptoms to your alternator, when a load was applied it would drop just below 13v. I changed the alternator myself, it took 2h out and about 30min back in. doing it again, i could probably have it out in about 30. it is a bit of work but only nut and bolt work. Its a good excuse to change the belt and i replaced the tension idler at the same time as the bearing was trashed.