99 Forester Charging problem

99 Suby Forester, New Battery, Starts, runs, drives once jump started.

Am I really looking at an alternator? All accessories work when car is running.

Or

Do Subies have something quirky in the charging system?

Also.. in a 15 mile trip from the office to home, the check engine light would come on, flash a few times, and turn off... not sure if related.

I have a used OEM alternator that you could try (several in fact).

We could also read the code. The last flashing Subie CEL I had was due to bad valves. The CEL was for a misfire code.

Has the valve clearance ever been adjusted? How many miles are on it?

Have you tried replacing the battery terminal ends (on the vehicle side, of course)? I had a '92 Legacy that had a similar problem; cured it for me.

measure voltage with the car running. vary RPM while checking voltage. Voltage should remain fairly constant if alternator is good.

it's just barely over 100K, I did replace the ground battery end when the new battery was installed. The Positive looked good still.

I'll check the voltage tomorrow. No idea on the valve clearance. It's the companies car & maintenance has been so-so

Does it charge both at idle and higher rpm? When the first alterntor on my dads quit it would stop charging over about 2k. Could be an alternator, but also could be corrosion problems in the starting circuit. Hopefully its not the alternator, rebuilds only last about a year ( I think my dad has been though 4 or 5 since the first one quit).

Doesn't seem to charge at all. cleaned the contacts I could reach last night and drove it back across town this morning.

Backed into it's parking spot, turned it off. No juice.

I'm not going to play with it anymore right now. Company can send it to the shop

I've had alternator problems with all my subies, and they always seem to make me scratch my head. Best to buy one, and see if it solves the problem....you'll need one eventually, so even it it doesn't solve the problem you'll be glad you have a spare on hand at some point. They never completely fail, just go out of whack enough to make you wonder what the hell is going on.

Add an extra ground to battery ?

Ah, alternators are simple. Fiirst thing to do is check the voltage. Should read app.14.3 volts just above idle. The small wire on the alternator sometimes works loose. The most common thing with high mileage is that the brushes are worn out. Did the charge indicator,sometimes thought to be the battery light come on ?