e-man

Hey guys. Here's the situation. 99GS4, 143k. New battery from Costco 6 months ago (the battery in the car at the time was 5 years old and died). I installed it myself. I noticed some corrosion around the terminal clamps, but didn't take the time to clean it off. After installing the new battery, the car started fine, so I wasn't concerned. It has started perfectly for the last 6 months.

Fast forward to a few nights ago. The car was parked outside for a few hours in cold (but not frigid) temps. I went to start it and it was slow to turn over, but it started. Drove home and parked it in the garage.

Next morning, same thing, the car was slow to turn over, but finally started. I drove around all day, starting and stopping probably 5 times, and everything was fine. This morning, the car wouldn't start at all. There was no power (not even enough to honk the horn).

I went out and bought some wire brushes, came home, took the clamps off the terminals and gave them a thorough cleaning. I removed a lot of corrosion. I put the clamps back on and figured I'd need to jump start the car (because it was completely dead 30 minutes earlier). Just for kicks, I thought I'd try to start it up and sure enough, it started right up. I let it run for about 15 minutes.

A few hours later, I went back out to try to start it and, once again, it was very sluggish to start. It would turn over a few times and then just stop. On the third try, it turned over just enough to start up.

One last tidbit. The clamp on the positive terminal is not very tight. I can twist it back and forth. I tried to tighten it after I cleaned it and, for whatever reason, the nut won't tighten (maybe the corrision?).

Any ideas what's going on here? I called Costco, and they said they would replace the battery, but that it was more likely that something was draining it as opposed to it not being able to hold a charge.

Any help would be greatly appreciated. Mods, if this belongs in the maintenance forum, please feel free to move it. Thanks.

e

tmf2004

iTrader: (15)

Well it very well could be a bad battery with a bad cell... Maybe something is draining it.. but the older battery lasted 5 years so not sure if its a draining problem..

e-man

That's what I was thinking too. The other thing that's strange is how quickly the problem came on. One day fine/perfect, the next day problematic, and there doesn't seem like there was any event that brought it on (e.g., extremely cold weather, running through a puddle, etc.).

If something is draining it, I would have no idea. I checked all my interior lights and the trunk light and I can't find anything that's stuck on. I guess I could always just get the new battery from Costco tomorrow. If that solves the problem, great. If not, at least I ruled out the battery as the cause. If it was a bad cell, though, why would it take 6 months to become a problem? You would think that it would have had symptoms right from the beginning, no?

e

AshburnM3

first thing i would do is to tighten down the battery terminals, use a small sheet metal screw if you have to. then i would test the alternator making sure it puts out 14v. if alternator is good, terminals are tight, then get a new replacement battery from costco.

e-man

The problem is that I can't seem to completely tighten down the positive clamp. I mean, it's not loose, but I can still twist the clamp after I tighten it (and maybe even pull it off). If you're suggesting that I remove the screw from the clamp and replace it with a different screw, I don't think that's possible. That screw looks like it's fixed and only the nut tightens and loosens.

How do I test the alternator? If I pick up a voltmeter tomorrow, would I simply test the voltage on the terminals with the car running? Assuming it tests at 13.5 or 14 volts, does that necessarily mean it's a bad battery? Is it possible that the alternator is properly charging, the battery is properly accepting/holding the charge, but there's something that's draining the battery when the car is off? I would have no idea what that could be, because I've checked all the obvious things (internal lights, trunk light, etc.).

Thanks for your help.

e

a#'z

Have you guys ever notice your inside door lights stay on,, after you close the door for about after a minute? it's a low dim.... Mines stays on.. wondering is it just my car...anyone? over time, my battery start to drain, i think it's due to that. i had my battery for about 14 months.. and i had to replace it.

5t341th

iTrader: (16)

sounds like a bad alt.
u can take it to autozone or kragen.... or w/e the Eastcoast has.
they can test it for u for free

e-man

So if the alternator is bad, would I still be able to drive the car around all day, starting and stopping, without a problem? I'm thinking that's possible, but only if the alternator is still kind of working, but just not fully charging the battery.

If I had a voltmeter (which I don't), would that be the easiest way to check it? If the car is running, the battery should be reading 13.5 to 14 volts, right? If it is in that range, does that mean the alternator is fine?

NemeGuero

iTrader: (15)

Get new terminals.

They're like $5 for a set at kragens.

Take the battery too, they'll be able to tell you if its **** or not.

e-man

Very strange. The car started right up this morning. No hesitation, no slowness, nothing. Now I'm totally confused.

jcat_350

here's a test of the alternator: start the car, and then remove the negative battery cable. If the car stays running, your alternator is fine.

e-man

Thanks for the tip. I'll give this a shot later today after I replace the positive terminal clamp.

By the way, what's the theory behind this?

NemeGuero

iTrader: (15)

battery is only used to START the car.. alternator keeps it running.

If the engine dies, that means the alternator is bad.

www.howstuffworks.com and search alternators

e-man

Thanks. Very interesting. I always thought you needed the negative terminal on to complete the loop.

jcat_350

negative (no pun intended). The battery just produces the driving force to kick the engine over. Think of it like the olddddddddddddddd school cars you used to have to actually crank...the starter does the same thing, just battery powered vs. hand crank.

If you really wanted to, I think you could start your car with a 12v cordless drill battery.

The alternator is wired separately to produce all the current for the car, therefore if you disconnect the negative battery terminal it should still run. However, disconnecting without the alternator spinning will eventually drain the charge from the electronics, thus ECU reset, etc., much like the slow drain of a PC power supply when you take the power cable out.