99 Z34 3.8 yesterday car wont start after a 50 mi trip to knoxville. Wound up replacing the starter and battery.Today we go out to eat and barely made it home.Car is dead again.There have not been any indications of alternator issues. No dash light warning,nothing. Stopped to have system checked, of course theyre closed. Anybody have ideas whats wrong? Muley

 

It does sound like your alternator is not charging your battery.

 

Yeah, sounds like another bad alternator.

Take it back and have them exchange it, they will have to test it first before they will give you another one. At least that is how Autozone is. No idea about the other McAuto Parts stores. lol

Remanned alternators are hit and miss. I have a Remanned one from Autozone on my 3.1, been on there for a couple years now at least. But I have heard of people get multiple bad ones in a row.

Also have a Duralast Platinum AGM battery in there too.

 

Guys, I havent replaced the alt yet. Probably the original but I dont really know for sure.
Just dont understand why it killed the new batt overnight. I charged it all day, took it to check charging system and passed. So I drove it work today wo any problems so far.Tomorrow may be different. I have replaced the coolant elbows recently and meant to r/r the idler pulley and of course forgot. What bugs me is if the alt isnt up to par, no dash light to show a problem.Will see if batt is ok tomorrow. Thanks for all your help. Muley

 

I would get the altenator and battery tested there was a time where my starter testes good 2 out of 5 times....I'm sure the same can happen to them. If not then something is draining the battery

 

plus I am sure you have to get all the components inside the alternator warmed up before it starts causing faults in the system, so it definitely needs to be tested multiple times.

Same thing applies with ICMs, at autoparts stores we are told to do multiple tests on the icms to make sure they get good an hot, because that is when they start showing failures.

 

Okay,Ive been driving the car since Tuesday with no problems. All I did was charge the batt overnight and go.When all this happened I had no choice but to buy a W-mart batt.Didnt want get a higher priced batt if that wasnt the problem.Had been running a Deka batt,only 4 years old so it could be the culprit.This car is all original,bought from my brother.He was a type of guy that if there are any issues,fix it now no matter the cost.Ill keep an eye on the batt for now,maybe all is good.
I thank you for the input. Muley

 

I know this thread is 2 months old. I have the same car as you do. A few years ago I started having weird elec problems. Replaced the alternator, it went bad right away.

Long story, short I found out the positive battery cable had been rubbing on some metal, about a foot from the pos batt terminal and had rubbed completely through the insulation! I replaced the cable (and secured it from that metal), put a new alternator on. Fixed problem!

I am lucky it didn't cause much worse problems, like burning out the expensive computer or starting a fire.

 

Well, Ive not had any problems with my car since charging the battery.Dont have a clue what happened as to no start after replacing the battery.Everything is "normal" I suppose.This is one of the situations that makes one pull hair. I appreciate all info about this issue. Glasspilot, I havent checked the cable but I will.Thanks again,all.