DJRATEDR

i recently upgraded from my '92 ls400 to a '97 ls400 and i'm having issues with my charging system. instead of just taking it to the shop to have it checked, i assumed (since it was giving all the classic signs) that it was the alternator. $250 later ... it's still doing the same thing (radio cutting out, car running sluggish, windows and accessories acting funny, battery dying after several days, battery not charging) ... had the alternator checked and it's within range (13.5V - 15V). i have no clue. the guy at pep boys said it may be the computer (?). it tells the alternator when to charge the battery. HELP!!!

deanshark

This is why you don't bring your car to Pepboys. The alternator is always charging the battery. If I was you I would have the battery checked, not at Pepboys.

DJRATEDR

battery is new ... just purchased it 3 days ago, but since the alternator isn't charging it, it ran completely dead. he bench tested my core (original alternator) and nothing was wrong with it and when one of the service guys did a charging system test on the car they told me that the alternator wasn't charging the battery ... this was with the new alternator in it.

PureDrifter

iTrader: (10)

stop taking your car to pepboys...

deanshark

Correct!!!! They don't know S***. It's mainly kids just learning what a car is and they're experimenting on customers cars. Just b/c you can twist a wrench, doesn't mean you're a mechanic. The older guys there are guys that couldn't make it through any training, or drunks that couldn't handle a real shop. Take your car to an actual mechanic, someone who is ASE certified and knows how to use all the equipment. You'll save money in the long run.

vutown

DJRATEDR,

Is your car throwing any codes? That's the fastest and most accurate way of finding out what's truly wrong with your car instead of chasing the problem by randomly changing parts.

Sounds like there's a short somewhere. I know this might not be related, but just to give you an idea.. My friend's honda accord's battery kept on dying. Battery after battery. The alternator put out enough juice, his charging system was ok.

He finally brought it to a shop where the mechanic diagnosed it to have a short in some solenoid which kept on drawing power from the battery even after the engine was off. Go figure...

Good luck with this one. Let us know how this turns out.

Lazy

iTrader: (2)

Is the car stock? Height, stereo, lights? Maybe try to do the alternator test on the car? Where u remove a terminal when the car is on

DJRATEDR

i agree with the pep boys thing ... the reason i was there was because that's where i bought the alternator. advance didnt have any in stock. i was returning the core and was on my way home when the car seemed like it was dying on me, so i made a quick dash back to pep boys instead of being stranded on the side of the road. i plan on taking it to my mechanic later on when this rain dies down some. the car is stock for now ... have all the extras, but haven't installed them yet. i heard it's not good to remove a terminal while the car is running? something about sending power surges to components if the alternator is good.

DJRATEDR

UPDATE: today i went a purchased a cheap negative battery cable and ran it straight from the battery to the chassis ground bypassing the alternator (as some had suggested due to ground issues) ... didn't work! with my voltmeter hooked to the battery before and after the cable replacement i noticed that when the car is idling (before the battery died) i was at about 12V while the car was idling and dropped down to about 10V or less when i rev the car up, so it is definitely not getting any power from the alternator at all. i checked the fuses & fusible links behind the battery - all good. they're the only ones i can find. didn't check under the kick panel yet (dunno if any of those are relevant?). another thing is that i purchased the car with only the valet key, the underdash lock to the trunk release is locked and i cant access the trunk with that key, so if there are relevant fuses in the trunk - i'm screwed! also, i have no owner's manual.

DJRATEDR

didnt mean it tells alternator WHEN to charge battery ... i meant it controls the charging system period.

PureDrifter

iTrader: (10)

except it doesnt.

engine running=battery charging.

Skynet27

I have seen many alternators come out of the box bad. There not new there rebuilt and there are many things to miss or mess up when rebuilding. I'm pretty sure you just need another alternator. Thats why i recommend always buying alternator's and starters from the dealership, you'll pay more but it's worth it in the long run.

PureDrifter

iTrader: (10)

lol starter perhaps since they're a pain to get to, the alternator comes out in way under 1hr.

tenchu

This. No way i'd risk an aftermarket starter with all the work involved, but an alt isn't that hard, especially for $750 savings from the dealership

tenchu

Also, if you're die hard on avoiding cost, take your battery to AutoZone for a free test, even they can't really screw that up, they should be able to charge the battery to see if it will charge/hold a charge. Its possible that your battery took a dump after your alternator, and its just not holding a charge.