Alternator / electrical question

[n0tdan]

Ok, here's the story.

Within the last year my battery kept dying, so i went to Kragen Auto Parts and they did their battery test and said my battery was dying and that i should replace it (they said my alternator passed their test) so i replaced it. My car was happy for a while.

A few months later, i had to get a jump start again... so i went by the Sears auto department and the guy said it looked like my battery connectors were loose (new batter had slightly smaller connectors apparently and could be removed w/o tools even though tightened all the way) so he said could give me some pieces of lead and i could pound it down and use it to give a tighter connection. After that, it felt like the car started better and seemed to solve the issue (I didn't have to hold the ignition key as long, felt more uh.. peppy? starting and i didn't spend a dime!). all is good.

And now, the current problem.

this last month the battery died numerous times. twice one week, once the next, etc... went back to Kragen again (2 actually) and the first said battery was at half the cold cranking amps, but the alternator was fine and i should come back when i had at least an hour so they could run the full test on the battery. A few days later, i went to a second Kragen (1st Kragen suggested that it would be easier to replace the battery if it was bad because that's where i bought it) and they did the battery test again, this time the guy told me to turn on my heater and such, so i crank up the heater to high heat and fan to high and he immediately says "battery is fine, it's your alternator." cca were still at half the battery rating, but he said that when i turned the heater and fans on the voltage dropped down to ~12.

so far, over the last week, week and a half, i've not had to charge or get a jump. I've been using headlights and radio only, and very short bursts of fan/defroster mid drive during rainy days where i just had to (really sucks...).

cliffs:
<1yr old battery
cca @ 1/2 rated
heater + fan = ~12v testing battery
Kragen employee says 100% sure it's the alternator, no need to test the battery further.


Ok, Question time.

I got a quote (worst case estimate) from a local auto electrical shop, and it was suggested that i get
electrical diagnostics @ ~80-120
alternator @ ~170
labor @ ~140 (1.6 hours)

I can get an alternator online for 120-170 depending on shipping options / brand

Would it be a good idea to get further diagnostics? And, does it sound like it would be a good idea to skip more diagnostics and just buy the alternator and have it installed.
What about buying the alternator online instead of through the auto shop? My thinking is that if the wrong part is ordered somehow i wont have to worry about it if the shop orders it.

obviously money is an issue or i'd have just paid the ~450 and or whatever the costs already to have it taken care of.

thanks for any advice just milking my luck at the moment trying to get by until i can decide what to do.

 

[Colt45]

If the voltage drops to 12 under load, is an alt issue... Or you have connection issues, but you should have sorted that by now...

A lot of alts (bosch specifically) have the brushes and voltage reg in a replaceable module.. so if the reg or brushes are the problem, you can just change that.. two screws and $30, if it's accessible.
12V under load could be a loose alt belt too.. turn on the blower, headlights, rear defogger.. let it idle.. then tromp on it... do the lights in the dash brighten up? any squeaks? chirpy noises at idle with everything on?

 

[rhino56]

cheapest to just buy a small socket set and a new alternator. change it yourself.

 

[ehhhh]

Make sure your battery connections are tight & clean. If you have an older car buy a used alternator and change it yourself.

 

[CptCrunch]

I would try with an alternator, most of them have a life-time warranty, so even if it isn't the real issue, you still have one that is covered for the life of the vehicle, If you know how to, replace it yourself, or look online for a manual to do so. Very easy job, half hour at most. Dont do the electrical diagnostics, that is most definitely a waste of money.

 

[LTC8K6]

Your alternator was not designed to recharge a dead battery. And it really was not designed to recharge one many times.

IMO, your dead batteries are killing your alternators.

 

[n0tdan]

it's a 2000 Daewoo Lanos ><; according to the shop it's a 1.6 hour job (the lady at the counter sounded surprised after she looked it up... i guess i have a weird car?), and looking under the hood it doesn't look like it would be fun for me to pull stuff apart until i can get to it. in addition i wouldn't feel comfortable doing it blindly. It would feel like taking apart a computer and putting it back together when you're not sure what all the parts are, how to properly get to them, and all you've done so far is vacuumed and maybe upgraded the memory

Where would i find a manual online? any searching i've done in the past has left me empty handed unless i wanted to browse through random sites offering services.


Colt, i don't notice any change in brightness but I've not tried using the heater/fans since the last jump. As for sounds, some belt is making noise. at one point i had asked a shop about it when i had a brake check and was told it was fine. he sprayed something on the belt and it made the noise stop, but he said it would probably make noise again later and it does >.> and the noise is regardless of idle, running, acc on or off.

1 alternator, factory installed i believe >.> and i believe the first battery replaced roughly a year ago was the factory installed battery as well.

thanks for the advice all.

 

[BUTCH1]

Originally posted by: LTC8K6
Your alternator was not designed to recharge a dead battery. And it really was not designed to recharge one many times.

IMO, your dead batteries are killing your alternators.

Yea, the guy at advance told me a lot of people put in a new alt. and jump start the car only to find out the alt. trying to recharge a croaked battery can die quickly. Folks are supposed to fully recharge the battery before starting up w/a new alt..