ja ja ja! Thanks thebear. Yeah, the car is running OK as usual. The problem only arises when I take it on an uphill road which is abou6t once a year so I haven't had the chance to test it. I haven't had the chance to check the alternator as I have a very "inaccurate" analog multimeter. Although I know that the belt isn't slipping. As a matter of fact, I changed it a month ago or so.
Anyway, I'll be sure to tell you of any new developments.
Thanks a lot. You've been very helpful and I've learned a lot.
Muchas pero muchas gracias