New Alternator Installed, New Problem

I was haveing a low amperage issue on my 8 year old orignal hitachi alternator, so I opted out to replace it.

I bought a bosch alternator rebuild for 245$ at napa auto parts.

Everything is going smooth after the install of the alt, I go to napa about 2 hours later to return the alt core. I return the alt core, get in the car and crank it.

Car starts... My Battery and Brake light are on. They won't turn off.

Napa tested the battery, (still under warrenty at autozone gold duralast 925ca) and they said the battery was bad, could be why the bat light is on.

So I bring it to autozone to replace the battery, they tell me the battery is good but no signal from alternator.

I been driving all day on the battery, Im getting 12+ volts from my bat, so with the run around that I got. I just replaced the battery with one I had lying around. Still got the battery and brake light issue.

So its not the battery.

I've checked all the connections there all good. The light may flicker sometimes.

I've checked whatever fuses I think are related (the ones I can see). And there ok..

Did I get a bum bosch alternator? As far as I can tell the voltage on the postive post of the alternator is the same at the battery 12ish. It doesn't seem like the alt is putting out anything.

And how the hell do I get autozone to replace my soo called bad battery even thoe they say its good. Anyone with a "GOOD" battery tool shows the battery being bad. But again, I used a different battery and still had the bat and brake light.

If all connections are correct my bet is a dud alternator.

Here is a thread on similar pain that I went through: http://forum.planetisuzoo.com/viewtopic.php?t=13757

It describes some of the testing procedures.

Hope you fix it. :)

A good alternator on the Rodeo should be reading approx. 13.5-14 volts at the battery while idling. Easy way to test is get a cheap Voltmeter, and hold it to the terminals why your engine is idling.

They, Napa, sold you a bad alternator - should be covered under warranty.

It's possible the rebuilt by Bosch may not be as good as they used to be, I got mine over 4yrs ago. Maybe the quality has changed....I wouldn't be surprized.

Or, it could just be bad luck of the draw....but, it's the alternator, not your battery.

Well the replacement should arrive today around noon or tommorrow. And I should be able to get it installed.

I don't know where else to get a alternator, I had to special order this bosch.

Everyone else has cheap remanufactured ones. This bosch is a premium remanufactured.

new around here...

did you install the alternator correctly and are you getting power to it?

otherwise seems like a bad one

That's a bummer. I'm sure you went the NAPA route to avoid this hassle. I had good luck with mine and recommend it frequently, but I guess no rebuild is 100% guaranteed to work. I had a bad rebuild out of the box from Advance, tried a new battery, had the same result with the new battery, and had to get a new alt. Four trips later the truck was running right again. Good luck.

The alternator was installed correctly. And as far as I know its getting power. The previous one was. Never in the two years owning this car have I had the battery light come on. I would assume it is getting power. Not sure how I could test that.

Well today, alternator didn't arrive, should arrive tommorrow.

So I got bored and I removed the postive wire > battery and ran the car with the alternator running to see what voltage was coming out of the postive alternator post.

I put my multimeter on the postive post and the ground on the alternator block and or engine block.

I only got 1v.

So I guess that perfectly stats the alternator is bad. It must have just died completely. Mabye the regulator failed.

This is beyond annoying. This makes me want to cry for petes sake.

New Bosch in, Was fine for about 15minutes then light came on.

I got my orignal somewhat still working alternator im just going to put that back in for now.

This is not right at all :(

Napa retested the battery, he said the battery was fine.

As I have nothing else to offer, I'll just say that many folks have gone through more than 2 rebuilds to get one to work. Good luck.

What is the odd thing is this was a bosch brand. The one everyone recommends. And I did two of those.

What appears to be the issue, is mabye the cut on rpm is too high on this bosch's or somthing.

Or mabye wiring is different not sure..

But im sure a oem honda will do. But whatever. Thanks guys for the help.

I'd be irritated too.

As I have a bosch alt and it's been the best alt I've ever used; quality's probably taken a dive just as it does with everything.

Klownicle... yikes,how frustrating. i think too it is possible that it's the 'new' alternator, but i doubt it.

it would appear there is *something* not right at all for sure; and it appears, from your experience so far, that the *something* must be within the charging system that is causing this problem. it almost rings a bell, but not quite...
thinking out loud...the newest bosch remanufactured unit worked fine for 15 minutes and then, zap you got the same problem.. did you do anything different in that period. did you try running w/o the audio turned on?
it's as if a short is creating an alternator-eating demon, or perhaps a diode-eating creature....you've been down all the paths, i know, but it still seems like it's some ground problem to me causing the electricity to search out a different path...have you tried disconnecting the audio, including the illumination connectors to see if that affects a change? have you tried tracing, ohm checking, the circuit that supplies the idiot light?

that's it so far....

//bc

including the illumination connectors to see if that affects a change? have you tried tracing, ohm checking, the circuit that supplies the idiot light?


Not sure how to do any of that.

But again. Everything is PERFECT with my Core orignal. Only the 2 Bosch alts cause the lights to turn on and what not.

Both times the light came on at different times. And the light would flicker on and off as rpms changed. And at some point the light would stop flickering, and just be on solid.

If everything is PERFECT with your original core, then put it back in and leave it alone.

Your original thread was started because you were having voltage issues....IIRC

How do you know for sure that something wasn't shorting out your original alternator too??

Err let me correct that, not more or less a voltage issue.

And by perfect I mean, the alternator is working in the car without a battery light coming on.

I have low amperage, and I run a aftermarket audio system. And I wanted to replace with a new one so that I can get the best out of the alternator.

When the bosch was in, I noticed a improvement for the short time when it DID work on the first alternator.

My current alternator outputs 30-40amps when tested.

Its a 90amp alternator.

Also someone told me mabye I should try and get my current one just rebuilt? Is this a good method to go?

...
Also someone told me mabye I should try and get my current one just rebuilt? Is this a good method to go? it depends on what you are trying to do. at this point i admit to being more than a little confused. but taking the alternator to a local shop that specializes in such work would at this point probably be the perfect solution -- they will test it first and confirm or deny a problem. tell them your saga succinctly, and you will no doubt get the real reason for your misery. at this point, it's more than difficult to look over your shoulder as to what you have checked in what order etc.

let us know what they say...and good luck.

//bc