fried alternator anyone?

[Voleurz]

so driving up to the airport doing 60 miles for about a good half hour after runnign it an aditional hour doing about 45 my charge light comes on and when i rev the piss out of it it goes away. i take it my alternator is fried?

 

ps. i made the whole 2 hour drive back home with it on as well. :S

 

 

:):):) pheew.

[Figbuck]

I'm not a mechanic, I just play one on TV.

 

What I have gone through:

 

The first thing to look at is your alt belt tight and not slipping. I have had the slotted alt bracket crack a couple of different times and I couldn't see it looking at it from the top.

 

Next maybe, the diode is starting to get punched through or it is leaking charge, right? A diode allows current to flow only one way and they fail eventually, so on the charge side, the circuit doesn't see all the current. Only a little leaking current will turn the light on, and it will run like that for some time.

 

A couple of times I just went to the dealer or import parts place and bought the diode for eight or ten bucks. The problem was that, then the bearings would fail or the windings would fail. The diode was a signal that the alt was at the end of it's service life. All the hassle of R&Rn' you could have stuck a new one in.

 

For all the times this has happened to me I should remember how to trouble shoot this. With the engine at two and a half, three grand, a volt reading should get you fourteen plus volts at the battery terminals.

 

Couple years ago, I lost an alt after about 65K of service. I was down in California and paid $85 for one at an import place, I think Beck Arnley. Changed it in the parking lot. I was under the impression that it was new Hitachi, not a reman piece of junk.

 

I was driving up I 5 all night. Stopped in Grants Pass for coffee and food. Came out and the truck wouldn't turn over. I'm parked on a slight incline, and bump start it. WTF?? I get on the freeway and in a couple of minutes, I'm thinking I'm loosing power or something. I look out and wonder if I had turned my headlights on, just as it starts to pop an backfire. Oh no, the engine is running off the battery and the battery is going down. I turn off the head lights and it perks right up, stops back firing. I lucked out and made it home.

 

I pulled the alt and took it to the auto electric shop. They hooked it up and said that it was FUBAR. A thousand miles and the bearings were toast. Sold me a 35 watt unit that the computer said had been on the shelf for 12 years. It was one that they had remanufactured and the computer said it was $39. It's still going strong.

 

Hope I'm giving you good info here... good luck.

[DanielC]

I have seen two two Datsuns quit charging, with the symptoms you describe. In both cases, they were fixed by replacing the alternator brushes. Take the alternator out of the car, and if you remove the two screws that are on each side of the plastic part that the "T" shaped connector plugs into, you can get the brushes out of the alternator. I do not know if alternator brushes are still available at a Nissan dealer, but if they are it is a fairly inexpensive part.

http://dimequarterly.com/

This website has info on charging system upgrades.

[Figbuck]

Right, brushes... I knew I was forgetting something. But still a sign that the unit has reached the end of it's service life. Go ahead an change the brushes and Diode, knowing that for the same effort you could do the upgrade to a higher amperage unit.

[Voleurz]

well, im kinda debating wich alternator im going with. i havent really ever had a problem with it... if it was the belt and not the alternator itself wouldnt the fan stop working so good too? im gunna call around an see what a new one is.

[Voleurz]

soi talked to my auto parts store and he wants to sell me a bosch or ac delco unit. for 80 bucks..

i said no thanks

 

then i call an alernator shop and he says he can bump up the amperage to 50. but for 150$

 

and if i can support the local guy who am i to say whats not good for me.

[pope_face]

Saturn swap!

 

There's that whole big thing in the "How To" section about putting in a higher output alternator, and apparently the Saturn one is the way to go. Go to a Saturn dealer and ask about one, or ask a shop you trust.

[RacnJsn95]

Why not run a 280zx alternator? They're 60amp... 70amp if you can find a turbo one.

[Voleurz]

Why not run a 280zx alternator? They're 60amp... 70amp if you can find a turbo one.

 

im not sure 100% what im doing. if the guy says he can juice the stocker up to 50 amps and its the same alternator... and that way i know its gunna be good for a while.. if i get one from a junker then it could blow in my face a month later..

[Guest DatsuNoob]

I got a 60 amp 280zx alternator from Bleach. I attempted the swap yesterday, and using stock bracketry, it appears to shift forward about 3/4" in front of the fan pulley, so the belt wont track evenly. I thought about cutting the lower bracket to shift it back, but it's friggin steel and who wants to spend a whole day behind a hacksaw? Who knows which lower alt bracket to get? I know some 720's used L20b's and 60 amp alternators. Is that the one to get? I'm almost ready to say fuck it and get a stock 35 amper for now, because I cant really wrench on my truck too much in an apartment complex without mgmt making a big stink about it. Maybe when I move I can get back to upgrading my electrical system. Anyone who's done this before, let me know. Sorry didn't mean to hijack the thread.

[Voleurz]

i think i will get mine rebuilt by the speicalty shop.

 

do alternators normaly get really hot?

[slodat]

There is a TON of info on this board about alternator swaps. I'm looking for it so I can post a link. Seems like this should be in the FAQ..

[banzai510(hainz)]

As Daniel C said it most likey the brushes

I had one go out. a nissan unit it seems the stator or whatever they call it was out of round causeing it to wear out faster.

 

Try going to Napa and they see lf they sell Beck Arney brand and they might have a up grade to a 50amper in in trucks, BUT the bigger alternators 50ampers tend to hit the idler arm and cant get the belt to fully tighten.

[DanielC]

Alternators can get hot. The wire gauge used in the stator is a few sizes smaller than the wire gauge you would normally use for the amount of current it carries. If the Alternator is trying to recharge a dead battery, it will put out its maximum output, and it will get really hot.

When the battery is fully charged, and all the electrical accessories are off, the alternator will cool off, but it will never go below the temperature of the engine compartment.

[Guest DatsuNoob]

There is a TON of info on this board about alternator swaps. I'm looking for it so I can post a link. Seems like this should be in the FAQ..

 

I checked out dime quarterly and saw the FAQ's but it didn't mention anything about lower alt brackets. I vaguealy understand what's going on with the wiring, I'm sure I'll get it better once I read it a couple more times and check it out under the hood. Electrical has never been my best subject.

[Voleurz]

its all in the how to section ive looked thorugh it already

[Voleurz]

how the fuck do you get the white and red striped wire off?

[banzai510(hainz)]

usually there is a 8mm nut that goes on a post.

http://catalog.eautopartscatalog.com/archsoftware/importedcarpartspfp/wizard.jsp?partner=pacific&year=1971&make=NI&model=510--001&category=F&part=Alternator&partnerSession=2cece33d90bf713844475bcbfe8b5c2c

[Voleurz]

i cant seem to be able to get that black cover off.

without resorting to violence that is..

[Voleurz]

ok stupid thing broke anyways. gotta put a new whatcha macall it on there now. the contact thing no clue what the proper term is.

[banzai510(hainz)]

the red wht wire should go to the post that held down with a 8mm nut.

the blkack scren I believe hide the bridge rectifier if I remember right but doesnt matter. You should not need to pull it off unless something broke like the post. But you made it should like the red/wht wire was still ON.

[Voleurz]

no no. the black cover over the 8 mm bolt like the proctective rubber booty thats since turned rock fuckin hard... it broke and along with it the flimsy electrical contact.

i left the screen alone.

 

do you happen to know what guage wire that is? the white red striped one?

[banzai510(hainz)]

I had one alternator where the post broke off inside(kinda like your situation). I just went and got a new alternator(since I have a few NEW nissan ones in the box). As the one on there was a Schucks special from the previous owner

 

As for gauge I think 14 would cover it. Going bigger isnt going to hurt it. Hell go 12awg

[ppeters914]

I thought about cutting the lower bracket to shift it back, but it's friggin steel and who wants to spend a whole day behind a hacksaw?

 

Awwww, suck it up you sissy! :lol:

 

Seriously, I had to hacksaw an inch or so off my alt mount for the GM alt conversion on my roadster. Took about 30 minutes of on/off sawing and then filing it flat.

[Guest DatsuNoob]

Awwww, suck it up you sissy! :lol:

 

Seriously, I had to hacksaw an inch or so off my alt mount for the GM alt conversion on my roadster. Took about 30 minutes of on/off sawing and then filing it flat.

 

It's not only that I don't want to cut it, tap a new hole through the front, etc, but when you do, you have to add an inch to the rear of the bracket to mantain the same width. That means adding washers, which to me is hokey as shit. I'm thinking it would just be easier to make a new one outta 3/8 flat stock with 2 short pieces of angle iron welded and drilled. Bobs your uncle.:fu: