Why won't my car start?

September 27, 2009 9:39 PM

Why won't my 99 chevy malibu start?

open the door, the dome light comes on. put the key in the ignition and turn it past acc and all the lights die. it doesn't even attempt to crank or turn over. take the key out of the ignition all the lights come back on, dim at first and then they brighten up. with the key in or out of the ignition, pressing the brake pedal also makes the lights die (and taking my foot off the brake has them all come back dim and then brighter).

the other day i had a theft system/pass lock problem described here and leaving the car alone for 10 minutes fixed it.

today, no blinking theft light and leaving it be didn't fix it.

posted by nadawi to travel & transportation (10 comments total)

Bad battery cables - probably the ground.
posted by torquemaniac at 9:43 PM on September 27 [1 favorite]

If not bad battery cables, then a dead battery (likely a cracked plate). It's got enough left in it that it'll supply the few hundred milliamps for the interior llght, but not enough to supply the 10's of amps for the starter solenoid, or even the couple of amps for the brake lights.
posted by Pinback at 10:43 PM on September 27

Try the easy things first. Look at the battery terminals and if there's any sign of acid residue (usually a greenish powder) or if it looks very dirty and gunky, disconnect and clean the lugs and terminals with one of those cylindrical two-piece brushes you can get for a buck or two at the nearest auto zone, then put them on good and snug.

(If you don't know the basics of battery safety, do not do this yourself. You have to be aware of every possible way that you could inadvertently short the positive to ground or the negative terminal directly or indirectly, so if you're not sure you're that person, have someone else do it.)

Then either put it on a charger for a few hours or if you don't have one, get a jump start and drive it for a half hour (in the daytime so you're not using your lights). This has been the problem for me about half the time.

However, even if this fixes it for now, the battery is very likely on its last legs, so expect to have to replace it soon.
posted by George_Spiggott at 11:05 PM on September 27

battery
posted by at the crossroads at 1:09 AM on September 28

If the battery is at least three years old: battery.
posted by flabdablet at 2:15 AM on September 28

Your battery is completely kicked.

I suspect that your two problems are unrelated, however. The problem that you're having with your anti-theft/immobilizer system is a pretty common problem on Chevys of that vintage. I've seen it go bad on Malibus and Impalas a few times. The most common failure that causes this problem is a malfunction of the ignition switch. There's a transceiver in your key and a sensor in the ignition switch. Every time you start your car, the ignition switch interrogates your key to make sure that you're authorized to start the car (as opposed to jamming a screwdriver in the ignition and stealing the car). When the sensor goes bad, the car just sort of assumes it's being stolen since it can't detect your key.

So, a new batter and a new ignition switch should get you back on the road.
posted by Jon-o at 4:25 AM on September 28

Battery should be first item on list to check. One way to do that is to get a jump start from another car; if it works, then most likely your battery is the problem. They can fail at any time, but most likely after 3+ years or 5+ years in moderate climates.

Obviously, don't attempt this yourself unless you know what you are doing with potential to damage electrical system on either car or for injury.
posted by Kevin S at 6:07 AM on September 28

I'm going to agree and say battery. Things act screwy when the battery dies---there's enough energy to turn on lights, but not enough to start the car; all the warning lights in the dash turn on etc.
posted by luckypozzo at 6:39 AM on September 28

Agreed- most likely dead battery, or loose/corroded connections. It was probably the source of the passlock problem.

The reason things get weird when the battery starts to go funny is that the newer cars' computers don't just measure "on" versus "off" for various signals. It measures voltage differentials. If the voltage is all fluctuatey, it will read those differentials wrong. I've got a 1997 GM, and it goes absolutly nutzo when the battery gets funny. Biggest reason is that the multifunction turn signal stalk uses this kind of signalling to turn things on and off. There is one wire going in, and the different switches apply different levels of resistance onto the return wire. The computer reads the voltage drop on the return wire to know what to turn on. If the feed voltage is wrong, it can interpret the "turn left" signal as "windshield wipers".

The other thing is that one of the ways lead-acid batteries can commonly fail is that it will happily provide proper voltage at a low current- so the interior lights work fine, and a volt meter shows it's fine, and the charging system shows fully charged. But if you put a larger load on the battery, it drops dead. Pinback is right, it's a damaged plate inside the battery. It is the surface area of the plates that determines how much stuff the battery can power. If one of the plates has gotten smaller, it reduces the power producing capacity of the battery.

(The other, other thing is that a bad connection can eventually ruin a battery. The battery can supply enough power for a while, but since the bad connection also determines how much charge it can take, it will eventually be always starving for full charge, and slowly kill itself.)
posted by gjc at 7:07 AM on September 28 [1 favorite]

Do you have an aftermarket stereo? My girlfriend had a similar problem with her civic; it turned out the installer had left a mess of wires that melted, corroded, and shorted.
posted by CharlesV42 at 7:26 AM on September 28