Ahhh. It's highly doubtful you have a battery problem at all. You have a starting problem. The part that confused you is the jump-start. It sounds like you have an intermittent starting problem. It cranks at times and not at other times. And it just happened that one of those times it started you had the jumper cables on it. That used to be real common on Chryslers, Hondas, and Toyotas with the little silver Nippendenso starters, and it had an inexpensive fix. That was to put new copper contacts in the starter solenoid.
I haven't heard of that being a common problem on GM vehicles so we should look for other causes first. Typically that would be a poor battery cable connection. The clue to burned-away solenoid contacts is the starter will work if you just keep on cycling the ignition switch repeatedly. At first it might take four or five attempts, but as the problem gets worse, it can take dozens of attempts, or in my mother's case, I ignored it for so long, that she lost count after 700 attempts, but eventually it did still start.
To find this you need to catch it when the problem is acting up, and you have a helper to turn the ignition switch. Use a digital voltmeter to measure the voltage between a paint-free spot on the engine block and the larger terminal on the starter. Place the meter probe right on the copper stud on the starter, not terminal on the end of the cable or the nut that holds it on. You'll find full battery voltage there. It will be 12.6 volts if the battery is fully-charged. Now have your helper turn the ignition switch to "crank". If the starter cranks the engine, you should still find at least 9.6 volts, but the goal is to see what you have when it doesn't crank.
That click you mentioned can be one of two things. There's a light click of the starter relay, but that can be confused with all the other relays turning on and off during cranking. And there's the rather loud clunk of the starter relay. If you're getting that loud clunk, the critical piece of information is what that voltage is. Does it stay near 12.6? That points to the starter solenoid. Does it drop to 0 volts? That's due to a bad cable or connection and we'll have to narrow it down.
The additional clue that this is not a battery problem is the head lights or interior lights. You'll see they're nice and bright, and they don't get dim or go out when the starter isn't working. If this was a battery problem, the lights would go out when the starter engages.
Saturday, September 13th, 2014 AT 7:36 PM