Another car wont start thread
 

Had my car towed tonight. I tried cranking the car with the key but all it did was click really fast. When I had my headlights on they dimmed as well as the interior lights when I tried starting the car. The tow truck tried jumping the car and it ALMOST started. All connections to the battery and alt. are good. The alt has 88k on it and god knows how old the battery is. The same thing happened on my Blazer and it turned out to be the alt. When I locked my car with the keyless entry not too long ago it beeped quieter and the lights flashed dimmer. So tomorrow I'm replacing the battery and alternator. Does it seem like these components are most likely the culprits? I'm pretty sure of it but a few other opinions wont hurt before I drop over $200 to replace them.

Do a few checks first before you buy anything. First check all the connections and be sure to check the ground cable at the body and the engine. This one gets missed alot. Use a multimeter and see what the battery voltage is both before and during cranking the engine. Check 2 spots. Goto the positive terminal and negative terminal with the meter. Note before and during cranking. If voltage goes lower than 10 volts when cranking either the battery is really discharged or it's bad.

If the voltage is higher than 10 volts but you still have the same symptom, check the voltage with the meter at the positive terminal and at a clean metal spot on the engine. If this voltage is a lot lower than across the battery then a ground cable is bad.

I'm assuming that when you tried to jump it the battery you have is sucking up everything you can give it from the jumping vehicle. This would be 1 indication the battery is bad. It's easy to check the alternator once you have a good battery. You could try jumping the car from another vehicle but disconnect your existing battery. Be careful of the wires not touching.

Once you have the new battery in, you can check the voltage across it(positive and negative terminal) with a meter to see what it is before the engine is running and after it is started. Once the engine is running the voltage across the battery should be like over 13 volts if the alternator is working.

If the voltage across the battery doesn't go up after the engine is running, than you have an alternator problem of some sort. I would not just buy an alternator without checking it's function first. Worst case buy the battery first and then decide if the alternator is bad. DON"T buy cheap crap from places like advance or autozone. There electrical parts are pure crap and you'll be changing them out again in no time. Don't let people tell you they have a lifetime warranty either. A life time warranty is little help when you're stranded 12AM one night somewhere. Not to mention the labor either you have to expend to replace or pay someone else to replace it. Pay a little more and get good parts. By the way, Exide makes a good battery and Interstate (made by Johnson Controls) is pretty good too.

Sorry long

Thanks for the input. I guess that's what my project will be today. Thanks again.

i have seen cars click but not turn over when the batteries are shot.

You're welcome. Post if you have any trouble.