Alternator Problem

My 2008 Tundra Grade 5.7L 4x4 has an unusual alternator problem with 148000 miles on it. When I turn ignition on the battery light will come on and upon start it goes out as normal. I noticed the voltage gauge being between 9 and half way mark which means it was not charging. Voltmeter check confirmed it was not charging. I have researched and checked all associated fuses to be good. I have not checked right at alternator yet as it will be a pain to get to. Has anyone else found the alternator to be bad with the light acting normal? Before I go further I would like to have an alternator to replace on hand if others have had this kind of problem and replaced the alternator and not just bad connections at alternator. From what I read the average alternator lasts only 7-8 years and up to 150000 miles. I have had many cars go over 200k with no alternator problems and wonder if this is just a Tundra problem. Seems to me that charging cable from alternator to the fuse would have a bad joint at alternator since the alternator is telling the light not to come on as alternator is saying everything is fine. I know strange things can happen for it to be a failed alternator and just checking to see what others have found. Also thinking to be preventive and replacing anyway if this is a common problem with Tundra...Thanks

 

I've replaced every alternator on every vehicle I've had. Sometimes they last 150, 200k and sometimes they last 50k. This alternator on the Tundra appears to me like any other but I got a DC power and engineering one so that I can send it in to be rebuilt.

 

I replaced a bad alternator at about the same mileage on my 2008 Limited.

 

Did my buddies had 220k, opened it up and brushes still had plenty of life left about 25 percent. Toyota denso alternators are rebuildable as well, pretty easy to do.

 

Here is a picture of my brushes at 240k when my alternator got completely submerged in a mudhole, the alternator was actually still good, but the brushes got stuck into place from the mud and couldn't extend to the armature. Once that was clean it was good to go, but I replaced it anyway. I believe with plenty of patience and an inspection mirror the brushes could be replaced without removing the alternator if you needed a quick fix for some reason.

 

After checking all voltages at the alternator I diagnosed the problem being the alternator. A new alternator fixed the problem. Still strange that the monitoring IC regulator system within the alternator assumed all was well by not turning on the light. If it had not been for the dash voltmeter I would have been stranded. A voltmeter is all that is needed to diagnose an alternator problem. It was a gigantic pain to replace.

 

Do you have any resources for this? My alt needs new bearings, not sure how tough a job this would be.

 

If you look it up on the online stealership parts section, you can buy certain parts for the alternator, I think alternator bearings are in there.

Here's a link
https://www.sparksparts.com/oem-par...0dW5kcmEmeT0yMDA3JnQ9c3I1JmU9NS03bC12OC1nYXM=

 

My 2nd Gen totally cooked it's original alternator at 110k and just recently again at 230k. The last time I had problems with alternators was in the 90's on vehicles built in the 70's and 80's.

 

Was the replacement OEM?

 

Couldn't say for certain as it was sourced by a sole trader who just rebuilds alternators. The new one definitely isn't. And considering that the first replacement lasted longer in miles and years than the OEM...

 

What was the cost? I just found a place that rebuilds them in my town. If getting it rebuilt with new bearings and brushes are $100 or so I may go that route.

 

Just over $300 from Advance Auto. I would have looked into rebuilding the first replacement but I needed to get her back on the road for work. I didn't have any option with the original, it was totally fubared, I seem to recall that the stator was the only part that wouldn't have needed replacing. Once upon a time it was easy doing repairs on alternators but nowadays they are filled with electronics and not so simple.

 

You can get a Denso reman one for $150 on RockAuto. That's what I plan to do when my goes out.

 

I am seeing $255 for the 150amp and $248 for the 130amp Denso Reman there.

 

That’s weird. The 4.7 must be cheaper but don’t know why

 

Rocko9999, you are looking that the original price. You have to send them your core like any other parts place that sells remans.

 

Ah, you are right. I wasn't reading that correctly. Thanks. Looks like mine is $182.79.