It sounds like a cracked regulator IC problem in the alternator to me.

Below is what I heard from a company owner who runs an alternator rebuilding company. He said," Many after market regulators are not as good as Denso's and do not last long. He found most of those tend to have cracked IC problems and show intermittent charging problem in a few years.

He added," Denso has many special test equipments for the heat cycle and the heat shock tests and they design and make parts to pass all those strict tests. But after market ones may be not and I find many cracked regulators among them since a regulator is heat cycled every time a car runs."

I know many Celsior owners in Japan to have too low voltage problems within a few years after they have replaced the alternator. Those are all after market ones.

The owner also said, "We only use Denso's regulator to re-build the alternator not to have complains from customers but Denso's regulator alone costs more than $100 and I must say it's a bit too expensive."

 

I rebuilt my original Denso alternator, with a couple of special tools it is really easy - I knew the regulator was much better heat-sinked, than the aftermarket alternators

an alternative would be to get your alternator from a place like advance auto parts, who has a very small core charge ($22) and then you can just keep your original Denso alternator and steal the regulator from it and put it on the replacement alternator!

 

yes mine is... can you help me?

 

Deffo sounds like an alternator to me. I wish I would have rebuilt mine instead of replacing it. Was factory denso but now its an aftermarket one.

 

I think I bought my OEM denso for like $100 or so. Found it more difficult to find all the parts for a full rebuild.

 

Not for a new one you didn't, and I have never heard of a reman for that price level either!

 

Check battery terminal maybe that's just bad, happened to me

 

Well I took it to a indy shop and they couldn't find anything (which I don't believe). I still get the dim lights when applying brakes. I also replaced the connector on the alternator. I may just replace the alternator and get a Denso and never buy a Autozone anymore

 

Turn the ac, headlamps, stereo, and ws wipers on. Then check voltage at battery. If below 13v replace alternator. The system will not work right with less than 13v.

 

Check rockauto next time
110$
40$ core
Denso OEM
I have a 90' so it may be more for the newer models.

 

I went through 3 alts in 1month. Check your power steering system. check the hoses that go from the pump to resivior and vise verse. Even if they drip a little and you cant tell, its still enough to kill your alt. Remember liquide and electrical dont mix. I replaced mine and then put spark plug heat sleaves around the hoses, to prevent future decay of those hoses. I would bet this is the issue.

check the harnes, I have had the charge wire in a harnes rust through, your alt could be putting out the right amount but the battery might not be recieving it. but it sounds like it is recieveing a charge since its dropping.

 

Had the same problem last Friday night, I was leaving work and when I hopped on the freeway my radio and headlights kept turning off and back on, it was foggy too! Turned out to be poor connections from the battery