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taaron

280Z Alternator Problem

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So I have a 78 280z that I rescued from an abusive home a few months ago. Didn't run at all when I got it, but thats since changed. I've been test driving it and it died on me the other day. It led me to believe I have charging issues. I took a look at the alternator and its a recent upgrade from a 81 NA 280zx. The alternator itself is only putting out 12.3v when idling at 1300rpm. The "L" cable is only putting out roughly 11.8v into the alternator. When I swap this with a hot wire from my battery thats putting out 12.3v, the alternator starts making unbearable noises. From what I've read online, this zx alternator should be putting out ~14v constantly, however I've never seen above 12.5. I took it off and took it to autozone where they tested it twice and said it was fine. Battery is also brand new, bought it at most a month ago. 

 

I'm stuck, because the longer the car seems to be on, the more it seems to be draining. And after 15-20 minutes it will just be too drained to run and will die. 

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The 81 280ZX alternator is essentially the same alternator as the 1978, it's a direct bolt-in.  They're both 60 amp, it's not an upgrade.   You're right, there is no swap to worry about, no wires.  The L wire is there to charge the windings, 11.8 volts is fine.

 

The auto parts stores are well-known for giving misleading test results.  Just convince the guys at the store that it has a bad bearing, because of the noise, and get one of the free life-time replacements.  That's why they have the replacement policy, because so many of them go bad.

 

 

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2 hours ago, taaron said:

I've been test driving it and it died on me the other day. It led me to believe I have charging issues.

 

Battery is also brand new, bought it at most a month ago. 

 

I'm stuck, because the longer the car seems to be on, the more it seems to be draining. And after 15-20 minutes it will just be too drained to run and will die. 

 

Make sure that you don't have some sort of current draw that is draining your battery.  Are you jump-starting the car to get it going? 

 

It is very very very common for reman alternators to fail.  Many people get bad reman alternators directly from the parts stores.  The parts store should not give you too much trouble.  Their supplier is used to get a high percentage of the product back under warranty.  It's also very very common for the parts stores' test machines to show that they're not bad.  You have to be forceful.  They're used to it.

 

Search "reman alternator failed" on Google and you'll find stories that cover every brand of car.

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Managed to get the alternator replaced. Immediately its putting out 14v! Definitely looks like that was my problem. Now I just have to do some positioning better because the belt is squealing. Definitely looks like that solved my problem! Can't believe they even bother telling you your clearly busted alternator is still good. 

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