96 corolla altenator

[famlycar]

Does anyone know how long an altenator will last before replacement? Ive had the original one in when I bought the car in 96 till now but I would hate to have it break down on the road somewhere... any info on this concerning altenator lifetimes?

A carload of thanks.

[jdmccright]

I hope I don't jinx you by saying this, but in the years I've been trolling and modding the Toyota forum, I have never seen a thread where the culprit was the alternator...in any of their vehicles. In general, they are very reliable. To be fair, edmunds.com notes that the 1994-6 vehicles show the alternators as being susceptible to failure, I just haven't seen that pattern here.

You don't mention your odometer mileage, but make sure you are current on the major maintenance items such as timing belt, coolant replace, spark plugs, etc., before embarking on a long trip.

[DeltaP]

My last Toyota went about 225K miles on the original alternator. Then I merely cleaned it up and replaced the brushes. Ran it another 50K or so before I sold it!

[famlycar]

Thanks. I have over 200,000 miles on it already. What are some signs that an altenator is wearing out or are there any signs? and what would a fair price be for a new altenator?

[jdmccright]

$73 at AutoZone, plus $31.50 core charge that is refundable when you bring the old one back.

Obvious failure signs are the check engine light or battery light illuminating. Not so obvious are increasing noise from the bearings. You can always bring it to the parts store for them to test.

[Brian R.]

The only sign of impending doom is noisy bearings. If they die electrically, there is not normally any warning. If it does die electrically, your dashboard warning lights will act very strange (I think since they are not operating at a normal voltage which the alternator provides) and there will be at least three or four idiot lights on all the time. Also, you will find your car much more difficult to start. You can test the alternator output and there should be around 14 v if you ground the hot lead from the alternator to the chassis, using a volt-ohmmeter.

At least, if your alternator dies, you can drive it for a short time, the length of which will depend on the quality of your battery and how many times you shut the engine off and are forced to start it.

[DeltaP]

"You can test the alternator output and there should be around 14 v if you ground the hot lead from the alternator to the chassis".
__________________________________________________ ______________________
I don't recommend you grounding the hot lead from the alternator to the chassis, unless you want to finish it off. I think what Brian R. meant was to connect a volt meter and test between the hot lead on the alternator to a chassis ground. 14 volts would be good.

[famlycar]

OK, thanks. Sorry I don't get back to you right away.

My first battery I had in the car lasted about seven years; the next one about another seven years but the last one only 4 years (as I always cleaned up the battery during every oil change). Will this be some kind of sign also? or are batteries different as far as lifetime? Of course the batteries were not always the same brand but they were new. I did have the altenator checked last year at autozone where I got this new battery and they said it was good and the battery was bad, I can't remember the rating of 14v or whatever.

Also, how about installing the potential new altenator? anything I need to know before I begin?

[DeltaP]

I don't trust alternator bench tests,(Autozone,etc),that don't put the alternator under a load. Alternators are best tested in the vehicle with the proper equipment.
For your purposes connect a voltmeter between the positive and negative battery posts. A mininum of 12.3-12.7 open circuit volts should start a car... Unless a battery post is loose or there's some serious voltage drops in the wiring between the battery and starter.
Once the engine starts the voltage should climb as the battery is recharged. It should peak out at around 14.2 volts. ( Shows the internal regulator is working). Connect the voltmeter between the alt output,heavy cable and a chassis ground or the Negative post of the battery. You should get a similar reading.
Make sure you disconnect at least the negative battery cable before starting to change the alternator. Then check and recheck your connections before reattaching the battery cable. ( Battery cable: first wire off and last wire back on)! Start the car and make these voltage checks again. Hope this helps.

[Brian R.]

Originally Posted by DeltaP

"You can test the alternator output and there should be around 14 v if you ground the hot lead from the alternator to the chassis".
__________________________________________________ ______________________
I don't recommend you grounding the hot lead from the alternator to the chassis, unless you want to finish it off. I think what Brian R. meant was to connect a volt meter and test between the hot lead on the alternator to a chassis ground. 14 volts would be good.

My bad. Since I quoted a voltage reading, I implied that you should use a volt-ohmmeter to make that connection. Corrected my post for clarity.

[famlycar]

Alright, thanks. I got some helpful info here from all. I'll have to buy a voltmeter first and give it a test. Presently she starts real good and runs good and all.
Now, like you were saying Brian that there's not much warning so I guess the best bet is to replace it. Is a rebuilt just as good as a new one?

[Brian R.]

Originally Posted by famlycar

Alright, thanks. I got some helpful info here from all. I'll have to buy a voltmeter first and give it a test. Presently she starts real good and runs good and all.
Now, like you were saying Brian that there's not much warning so I guess the best bet is to replace it. Is a rebuilt just as good as a new one?

I would have to say that it would depend on the brand of rebuilt alternator. The only brand I would buy, new or remanufactured would be DENSO. Assuming they replaced the bearings and other parts which wear, they are as good. Personally, I would buy a new one from Amazon, assuming the difference in cost was not outrageous. I don't trust rebuilds, as a general rule. Sometimes you have no choice in that new parts aren't available.

If it is working now and there is no bearing noise, I would assume it has life left in it and it may outlast your car. Unless there are trouble signs, leave it alone. Normally, alternators die from being connected wrong - some electrical problem caused by disconnection or reconnection.

Another option is rebuilding it yourself. Here is a link to a simple electrical rebuild:

http://www.toyotanation.com/forum/10...lternator.html

Of course, if you want to replace the bearings, you will have to follow the instructions in the Toyota Service Manual. With no noise, you don't need bearings.