So I debated posting this because it seemed pretty trivial compared to other discussions. Nonetheless, I'm not too familiar with electrical troubleshooting on automotives so here it goes.

I can sometimes wait several weeks without starting my 951 and it will start up just fine. But I could also start it up, drive to home depot, go in, and come back out only to have my car not start. I hear the starter trying but there's not enough power to start the engine. This can also happen after longer drives as well.

I get it to start by connecting jumper cables and leaving them on for a few minutes, or by roll starting it. If the car has been jump-started, it will successfully start the next several times with confidence.

I thought that the battery must not be able to hold a charge, but its relatively new: march, '11. And I took it to autozone to do their battery test and the guy said it was fine.

I don't think it could be my alternator because once the car is running, the headlights are bright and I can listen to music (including an amplifier) without a problem.

Sometimes when I'm driving, the voltage will read exactly 12V, other times its slightly above that. I read older threads and they discussed the possibility of the voltage regulator being the problem, but I'm not very familiar with how I could check that. Based on these jumble of facts, what should I investigate? I have a digital multimeter and a current clamp meter at my disposal.

 

bump

 

No need to feel bad about posting.

Your symptoms seem to show a problem with the starting system.

Bad or low battery
Bad connections
Bad (worn out) starter
Bad alternator

Clean the electrical connections at the battery, the starter, the alternator, don't forget the engine to body ground strap connections (and battery to body).

Charge the battery with a battery charger, I often put a battery maintainer on mine (9 year old battery).

If you're getting 12 volts or slightly more, your alternator isn't putting out what you need. Good chance the brushes are worn out. You can just change the brushes (very inexpensive) or change the voltage regulator (new brushes come attached to it). Search how to do it.

Regarding your battery from 2011. Yes it should still be good but if it hasn't been getting a good charge from the alternator because the brushes are worn out or nearly worn out then the battery is likely bad. If the battery voltage has gone too low too many times the battery won't be very good.

One more thing. You could have something on the car that is drawing too much current from the battery when the car is parked. To test this you would have to remove a battery cable from the battery (engine off, key out) and measure the current (in miliamps) between the battery post and the cable. I don't remember the acceptable amount so you need to do a search for that.

Hope this helps.

 

Thanks, I'll try those things this weekend

 

Another thing, if you have dirty grounds and gauge cluster connections, then your volt gauge may be reading improperly. My volt gauge reads low randomly, it's the gauge not the alternator or battery. FWIW

 

Clean the main grounds on the back of the engine.