Originally Posted by
dscheidt
You assume it works properly, or that it's capable of actually charging a battery, and not just keeping a battery for self-discharging.
I suspect there's a large draw somewhere, like an aftermarket radio, alarm, or such. Or the battery has failed. I also suspect asking a bunch of bike commuters about fixing your car isn't the best way of doing things.
It could be so many things... starting with the battery is the first and easiest step before one tries to trace the wiring for a short or find what is drawing down the battery. If it is starting and then running well I would assume the alternator function is good.
I grew up with a father who ran his own auto repair shop... was turning wrenches on cars just about as early as I was turning them on my bike.
Now the new cars have reached a point where self service can be really difficult due to all the technology under the hood.
One should also check to make sure the dome light... interesting note on these is that my friend's father invented the automatic dome light when he worked for Packard.