How would I go about checking if the alternator is doing its job? I usually leave my FD sitting for awhile and don't drive it all the time now.
Last time I left it for over 2 weeks (on vacation) and it started up fine. (Back in December.)
Recently, even after a few days, I come to find the battery completely dead.
Last time, I jumped the car and drove for a short distance, then parked it (intending on taking it out again later) and came back to find the battery dead again. (This was less than 4 hours later.)
I'm going to take the battery to get tested in the next few days.
Is there anything I can do to check the alternator? It should read about 13-14v right?
Anything else I should check?
Maybe its just time for a new battery....

 

When was the last time you changed the battery?

It's probably just time to get a new one. I would pick up a new one and see if you still have the same problem.

 

It sounds like you may need a new battery. You should get something like 13.5 to 14 volts. The proper way to test the alternator is when an amp gage, but you need the right tools to do that. I believe Autozone will check your battery and alternator for free.

 

Why not check the ghost amp draw? Just stick a multimeter on amp mode between the pos terminal and pos battery terminal when the car is off, it should show that your amp draw is at 0.24 or so. If not, something is grounding out, just pull all the fuses till it goes down and you found your draw, then trouble shoot from there.

You can also test your battery by using a hydrometer (which can be bought at any local Kmart or auto store, cost like 5 bucks). Becareful of that battery fluid, its very strong acid and will eat your skin! You dont even wanna know what it can do when it hits your eye!

P.S. If you wanna check your alternator, you gotta get a special testor that can handle about 100amps. you can also take it down to your local Checkers and have them test it.


BTW: You should be charging your battery every 2-4 weeks or so. I'm amazed more people don't know this!

 

you can take ur car to an autozone and have them hook up there machine to test the battery and alternator. Its free.

 

I start my car at least every other week when I'm around. And drive it about every other week too. Maybe more often.

 

Yeah, I plan on doing that sometime this week.
Just need to find some time off work and school.

 

it dont matter

 

You need to drive the car around for probably at least 15 to 30 minutes to recharge your battery if you don't drive it very much. Just starting it and letting it idle for 5 minutes won't do work.

As far as charging your battery every 2 to 4 weeks, are you talking about actually hooking it up to a charger? If you drive your car somewhat regularly, you don't have to do this.

 

My car drains the battery in a similar manner. When the car was off one time I traced a faint humming noise to the alternator. Detached it and the hum went away. I now need to repair my alternator.

 

I have a disconnect switch on my battery so when I am not driving it I just twist the **** and no power will be lost through whatever ghost is stealing it. Plus it is a nice safeguard so hopefully no one will steal it.

 

Note that to test your alternator at most car parts stores, you have to pull the alternator. If you drive the car over to Sears, they can test the alternator while the car is running (run the fans before and after!!!).

 

if i crank my car at least once a month the battery will be fine, then i drive around to charge it. anything past one month and the battery is dead. it takes about 15 or so minutes for it to charge every month. 30 or so if it is dead

 

does anyone have a wiring diagram for the headlights??? some bastard hit my car in a parking lot (driver's side fender / headlight) the headlight turns on but doesn't pop up...if i don't remove the headlight fuse and park the car it drains the battery....it's a pain in the *** to follow the wires back from the headlight...could it possible be the motor trying to open the light???

 

Disconnect your ground when not driving the car for more than week or so.

 

I had the same problem when it first started snowing here in STL. I assumed it was the security alarm light, so now if I am not driving it I disconnect the negative so it doesnt drain.
Whats funny is that my car sat at the dealership for 3 weeks back in July and there were no problems starting it then. Perhaps it has something to do with cold weather as well.

 

Well, I took the battery to Pep Boys and they tested it in like 15-20mins. They said they fully charged it and tested it. The battery was in good working condition according to the machine they hooked it up to.
So, I came back and put it back in the car.
It sat for a day (while I was at work today) and well, the battery is dead again tonight.
So, I don't know whatsup.
I guess I have something draining the battery, maybe a short somewhere.
I had an alarm system installed not too long ago and I'm guessing it might be that, but am not sure.
I'll try to get ahold of a multi meter or something to test that out, or bring it back to the shop that installed my alarm and see if they can figure it out.
Anymore advice from any of you smart FD people?

 

I had the same problem too. You are taking all of the right steps.

Try cleaning the connections to the battery and then screwing them on super tight. It takes my battery more than 30 min of driving if it is totally dead to recharge. I think after you let it die so many times that can't be good either. If it wasn't a loose connection then try taking off the negative wire when you know the battery is totally charged and then come back a day later and see if the battery is dead. If not then you know you have a drain somewhere. Then you start pulling fuses and hooking up a voltmeter and see what is still on while the car is off. It's a huge pain though, the car is no good when it can't start.

 

usually when you charge a battery, it takes over 2 hours on high charge mode (which is about 15-30 amps charge) and about over night (afterwards) on trickle charge.

BTW: did you do the test to find what your ghost draw is???

 

Yeah, thats what I thought. Seemed kinda weird that they said the battery was fully charged after it was on the machine for ~20 mins.


Not yet. I'm usually pretty busy all day now and my car isn't parked at my house right now so I don't have alot of time to work on it during the week. I'll get this done asap though.

 

opps, i did not read the part where they said they charged your battery in 20 mins (which is impossible!!! It takes me at least an hour to charge up my double A batteries with a peak charger so how the hell can they do it in 20mins???)

 

I had the same problem early last year. I replaced the battery, and had the alternator & wiring tested but no problem found. I even blamed the security system, interior light, and the radiator fan for awhile...

The problem kept occuring and the shop finally figured out that the alternator belt was worn so that the alternator wasn't always turning.

Sometimes it worked, sometimes it didn't. When it didn't often enough, the battery died. I replaced the belt and have had no battery problems since. Knock on wood.

 

once one of the cells in your batterry dies then the battery is dead. i would take a gravity tester and test each cell (takes five min's), that's a real good indication of the life of your battery.
go buy yourself a multimeter. w/o your car on, the battery should carry ~12.5 volts. while the car is running, you should read about ~14.5-15 volts w/ a properly running alternator. i would also do what snook said and clean the terminals. maybe you do not have the proper connection to charge the battery.
nick