# 86 300ZX non turbo voltage issues.



## lshuntsman (Jun 30, 2013)

Please help. New alternator and new battery. The voltage gauge in the car drops from 14 to 12 every time I put on the brakes, or turn on the lights. This is the second alternator in just a couple of weeks. It was tested to make sure it was working properly before it was installed. Any thoughts as to what could be causing this?


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## smj999smj (Jan 1, 2006)

If it isn't a genuine Nissan reman alternator, I suggest you get one. Aftermarket electrical parts, from alternators to starters to distributors, have historically been problematic on Asian makes, including Nissan. Z31 alternators are a bit of a pain to replace, anyway, and who needs to replace several aftermarket units until they find one that'll last? At this point, load test your battery and make sure the connections are clean and tight. Make sure the alt belt is properly adjusted and check the circuits. If all that is good, you likely have another bad alternator.


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## AZ-ZBum (Nov 21, 2004)

As long as it's still charging 12V is okay. Once you can no longer run accessories, it's time to get a new one.

I wouldn't waste the money on a Nissan unit. You can get quality rebuilds from a better parts store. But I'm sure it's too late now to get your money back. Just keep getting their warranty replacements until you get a good one.


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## smj999smj (Jan 1, 2006)

12v is not an acceptable charging voltage. Acceptable charging range is 13.2v-15.0v tested at idle and at 3000RPM, both tested with loads on and off. I don't consider the extra money spent on a Nissan reman as a "waste of money" if it keeps you from having to replace the alternator again and again, but I assert a value for my time and don't like being stranded on the side of the road with a dead battery during a long trip. I've been seeing problems caused by low-quality, aftermarket reman electrical parts used on Nissans since I first started working for them in 1985 and while the quality of "some" aftermarket parts have improved, they haven't improved enough.


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## AZ-ZBum (Nov 21, 2004)

But Nissan won't replace the alternator under lifetime warranty like the auto parts stores. It doesn't take long to swap out an alternator. Anyone takes a risk on any remanufactured part. I won't buy electrical components from AutoZone or O'Reilly. They contract to the lowest bidder. I've never had an out of the box issue with the Pep Boys alts, but my last alternator purchase was from a local chain.


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## i r teh noobz (Apr 26, 2007)

I've had great luck with a local alternator/starter rebuild shop. Local shops seem to stand behind a product while chains boast a warranty.

86 NA shouldn't be too hard to change. I changed my 85 NA's alternator in 20 minutes. Its the later ones on the passenger side that give me trouble.


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## smj999smj (Jan 1, 2006)

A lifetime warranty is worthless to me if I have to change the same part over and over again. I remember back in the mid-90s a friend of mine (and salesman at the Nissan dealer that I worked in) bought a T11 Stanza hatchback. For those that don't remember, the alternator on that was on the back side of the engine, over the axle, and a real pain to replace. He put a Pep Boys "lifetime warranty" unit on it, despite my advice and ended up replacing three of those in a month's time before the fourth one finally lasted. I remember "World Parts" being one of those part remanufacturers whose parts were garbage right out of the box (or shortly afterwards). I don't mind paying a little extra if it means I'm not going to have to do the job twice. Repairing a vehicle with cheap, unreliable parts only results in owning an unreliable vehicle. That was the main reason the Japanese cars were so much better than the US domestics back in the 70's, 80's and 90's: the were made with much better parts. These days, you see a lot of cheap, third world manufactured parts being used in Nissans and other Asian makes and their quality has suffered because of it.


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## AZ-ZBum (Nov 21, 2004)

That's why you always have it tested before you leave the store. Alternators don't last forever, and once I found a good alt at the AutoZone, it lasted for several years.

Using factory parts is great, but where do those Nissan rebuilds come from? Are they sent to Japan? Or aren't they just sent to another supplier here in the states?


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## smj999smj (Jan 1, 2006)

At one time they were brand new parts put in boxes labeled "Remanufactured." I believe it was for tax purposes. When the 95 Maximas came out, there were a lot problems with the starters (they cranked the engine too slow, resulting in flooding). The replacement starters were updated to correct this. It was somewhere around then that I remember first seeing Nissan reman parts with signs that they actually were "remanufactured" instead of brand new. I believe most of their reman parts are made in TN these days, but made with all new parts, the same as those used in the production parts. A lot of problems with the aftermarket remans (at least the cheap ones) are low quality parts and shoddy assembly.


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