we just had a storm here in s.f and my car...PART NUMERO DOS

so, this morning i went to look at the truck to make sure it?s ok and not towed or spray painted on; or something like that. So, this morning i tried to start the truck but it just wouldn?t start, it wasn?t turning at all, and it sounded like it was the battery. i didn?t have jumper cables and no one was stopping to help me so i just left it parked there again. so, i went to work then came back this afternoon, the truck starteted and there it was, started on the second try. WOOHOO!! Yeah! i was sooo happy, so i said to myself, i better drive home and park it just in case of something, well good thing i thought that because once i had it parked, i tried to start it up again and it was turning but the engine wasn?t going and something was sounding in the engine like a small machine gun sound. what do you think it is?

thanks,

Alternator failure would be the first guess, followed by a weak battery - did you see any warning lights on the dashboard come on?

You got the truck to start this morning because of the "surface charge" effect, where a discharged battery sits overnight and can build up enough current for one good burst of power, and then it fades fast - if you can get the engine started on the "first pull" you're golden, otherwise you won't get a second chance.

The "machine gun sound" would be the starter solenoid chattering as it tries to pull in and start the engine, but there's not enough current available from the battery to do it.

First, if the battery is over 5 years old or more than a year past it's warranty date, it's probably gone. They die simply from time.

Go spend $20 on a decent digital voltmeter, and another $25 on a decent 10-amp battery charger. First, hook up the battery charger and get the battery back up to a full charge overnight, so you have a known starting point.

Then take a simple digital voltmeter and watch the voltage on the battery. With the charger disconnected and no loads (like the dome light) on, it should hold at about 12.5 volts fully charged. Then put on a light load like the tail lights and the battery should not drop below 11.5 volts, if it does the battery is probably dead or dying.

When you go to crank the car to start it, the battery voltage should not drop below 10 volts during a normal start.

And when you get the engine started, the alternator should be putting out 13.5 to 13.8 volts to charge the battery, depending on the outside temperature. (Hotter will be higher.) With the engine at idle and the headlights on, it can dip to the 12 to 13 volt range, but the voltage should pop right back up above 13.5V if you give the engine a little gas.

Try all this and tell us what happens.

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