When I am driving down the road at highway speeds, my battery light flashes and my volt meter bounces up and down (a little bit). If I turn on the lights the volt meter stops bouncing and the battery light shuts off.

What's up?

 

Sounds like a voltage regulation problem. Check your connection at the alternator first, clean it and see what happens. If it looks worn, buy a new connector.

If that doesn't work try a new voltage regulator, luckily they can be replaced and save you the cost of a new alternator.... only go that route as a last resort.

 

Thanks for your advice.

I changed the voltage regulator and the problem continued. I took the truck to my local Mexican mechanico ( I live in Mexico) and he pulled the alternator and took it to a repair shop. A couple of bad diodes changed and $30 got me down the road again. They even fix alternators here