I’ve got a 2002 Civic, and for the past few months (!) I’ve been able to tell the battery or alternator (I think) must be going, because it wouldn’t start a few times and I had to pop start it. Yes, I know I should have taken care of this much sooner, and to be honest there’s some other maintenance related stuff I’ve been putting off pretty much out of laziness/procrastination, but now I’m getting it all fixed (hopefully this weekend).
My question, is whether its safe to drive for a few days, or if I would be running the risk of it dying mid-transit. I’m fine running the risk of it not starting for me, but I don’t want to have anything happen while I’m actually driving.
Up until now, it had just failed to start, but the light didn’t come on. One time a few weeks ago, after it hadn’t started and I pop started it, it did run strangely for a while with the windshield wipers moving slow, lights dim, etc., but eventually it did return to “normal”. So far when this stuff has occurred its been while I’m running the AC and radio and headlights, and turning that stuff off has helped.
So, should I pretty much not touch it until my mechanic actually fixes it, or would I be alright being careful and driving it in the meantime?
Yes it may die in transit. This is the voice of experience. I was so stupid as to drive a further mile with my headlights off in order to make it to a garage - which I didn’t. Died a mile short. I still needed a tow truck to bring me to the service stattion.
Clean the white stuff off the battery terminals and make sure the connections are tight. Charge the battery overnight and then drive it and see what happens. It will be fine at first. If it keeps starting by itself, it’s good to drive. If you have to bump start it, there’s a chance it will stop on you, especially if you are using lights or AC. Your alternator is either putting out very low voltage or else the juice is not making it to the battery.
I had a friend that had a dead alternator and I kept her going for a couple of months by charging the battery every day. It wasn’t worth fixing because she was moving back to Hawaii. Having one of those portable jump start units with their own battery can be handy also.
Your battery is not charging. If you use too much juice, the battery will eventually die. The battery light means the car is using more power than it’s charging - output exceeds ingoing charge. Sooner or later the battery will die.
If it’s erratic - then the alternator is erratic. Odds are it’s the diodes (rectifiers). I read once that 90% of alternator failures are just one or more diodes burning out.
Whether you can get where you are going before the battery dies, depends on how far and what other stuff (fan, lights, etc) are running besides the ignition and running lights. The safest thing, as mentioned, is to top up the battery charge each night. The danger is that constant drain- recharge will kill a battery eventually, they are not designed to tolerate frequent deep discharges. Eventually it will hold less and less charge, and then it will die where it used to make it all the way through the trip.
(If you think the cops won’t ticket you, disconnect the running lights, ha ha).
Replace the alternator now, or that and the battery later… plus a tow.
(Although the above advice is a very good start. Be sure the battery terminals are connected clean and soldi.)
OK, you’ve all convinced me. I’m gonna avoid driving it until my mechanic (who will be doing this on the side) can actually fix the battery/alternator, and the other random micellaneous stuff I’d been putting off. I like the battery charger idea, and will do that before making the trip to the mechanic’s house. Thanks for the advice.
The other point to be aware of is that a charge warning light doesn’t necessarily mean a problem with the battery or alternator. It can be caused by the dampener on the harmonic balancer being worn. If that is the cause then, in the worse case, driving it can cause the entire flywheel and crankshaft assembly to fly to pieces: time for a new engine.
Driving carefully and driving short distances won’t prevent that happening. When it happens, it happens and your engine basically blows itself to pieces.
Unless you know how to check for wear on the dampener or specifically diagnose the cause of the charge warning, it’s a really bad idea to drive a car when the charge light is coming on.
In most cars the belt driving the alternator is run off the crankshaft. If the dampener wears the belt loses tension and begins slipping and the alternator ceases working efficiently.
The older cars could go a long, long way with a bad alternator or generator. I once drove fifty miles to my parents house. No lights, no radio, no AC. So my power drain was almost nothing. My car still had a distributor and points. No solid state at all.
New cars – have computer chips & solid state ignitions. They suck power like a vampire. I wouldn’t risk driving far with a bad alternator.
It’s probably too late for the OP, but you really don’t want to drive a car around if the charging system isn’t working right. Not only could you end up stranded at any moment, but lead acid batteries also tend to chemically self destruct if they discharge too far. You could end up killing an otherwise perfectly good battery and adding a significant chunk of change to your repair bill.
Nothing he’s said so far proves conclusively whether it’s the battery or the alternator. Easiest way is to charge the battery and then test it with a load tester. Most shops can do this. Batteries tend to fail much more often than alternators.
One other important thing about all this: If it is a bad battery driving too long with it can kill a good alternator as well. Alternators cannot run ‘open circuit’. Open circuit is when the alternator is producing electricity (i.e. spinning) but it isn’t connected to a (good) battery to ‘suck up the juice’. Diodes in the alternator can’t take this for more than a few moments and burn out. And a completely dead battery not only has no charge but may not be able to take a charge either. Which means you’ll be running open circuit and that will kill your alternator!
Long story short, get it serviced asap. Even if it doesn’t strand you your repair may wind up costing double what it should have (battery & alt!)