Alternator help, hopefully…

I hope the alternator is the problem and not something more sinister. When the battery light first came on the dash I got some supplies together and then noticed my dome light dimming and getting very bright. Then my radio would cut out. And cherry on top both my headlight bulbs and one parking light bulb blew. Both high and low beams. This is all within 6 hours

At this point I went to AutoZone to get battery alternator and starting system checked. Of course battery light was off and they said my starting system was bad? I don’t know how it works fine.

I know it was a fluke but at home with voltmeter with engine running it first read 15-17 volts jumping between those and then the battery light went out and then it read 14 volts like normal. Battery was normal voltage at rest.

Decided to take alternator out and check continuity and resistance of diodes, slip rings, and b terminal. They seemed fine and checked brushes not really sure what bad brushes look like so I’ll put a picture below.

The voltage regulator would jump between 0-3 ohms of resistance and then to 1000-1500 ohms. Not sure if that’s a fluke but I’m guessing voltage regulator is out (guessing my bulbs got a huge surge due to faulty regulator and blew) and as far as I know that part can’t be replaced and an all new or reman alternator is needed.

Any agreement, disagreement, or suggestions are appreciated.

 

1. Autozone no.

2. in general when folks look at replacing alternator or regulator people generally prefer to replace the whole alternator

3. there are tests that can be done on the alternator and battery

4. why not replace it. It’s old and has miles.

 

Any local rebuilders that are quality locally? I'd rather keep a quality one rebuilt by someone who knows what they are doing then some sketchy autozone alternator ''rebuilt'' by some 16 year old that replaced ONLY the bad part and tossed a coat of silver paint on it.

 

not that I know of, there’s some little mom and pop auto shops around that might do it. BUT this is my daily and idk what the turnaround is on rebuilding, seems faster to buy all new.

 

I would just buy a denso alternator and replace it.

 

The old joke about rebuilt starters and alternators is they get 500 from the boneyard, try them once. Half fail. The other half get painted and tagged as rebuilt.

OP, buy a reman alternator from Toyota. They don't sell "new" alternators anymore (learned this last year). Do it right and you only do it once.

 

The diode boards are the things to go, i looked into replacing myself but realistically a denso reman from napa was the better quicker option.

 

I'll add my two cents to the party. I have a great local shop that rebuilds alternators and starters and is only about a mile from my house. Cost to rebuild was more than a Denso reman. Part of my goal was also to check with them how much bigger/more output I could get to compete with costs of aftermarket beefy alternators like Mechman/DC Power and that also wasn't worth doing. So yeah, follow what others have said and buy a Denso reman or Toyota OEM reman (likely the same thing) and just do the job once.

 

Denso seems like the best bet.

OP how many miles?

anything else may not be as good and last. Sure Autozone has a warranty but how hard is the job and how many times do you want to swap it out. Seems like more of a last resort if that’s all that’s nearby broken down on a road trip. But that’s up to you. I know I’ve made the mistake of using a cheap shitty part for it to not work before. At least once.

 

It’s sitting at 153,000

 

This is correct

It's about a 2-3 hour job so think about how many times you want to mess with it too. My dad went the cheapo route long ago and it lasted a month, but at least it was a 10 minute job to R and R the bum one.