Guest bastaad525 Posted November 16, 2003 Share Posted November 16, 2003 Okay, my FOURTH alternator now is starting to do the shaky amp needle dance that tells me it will be going out soon. Which tells me this is more than bad luck or coincidence of getting bad alternators... there must be something else wrong causing the problem. It hasn't gone out yet, but the needle is jumping around like crazy, and I smelled that burning coppery smell when I popped the hood. This one only lasted about 2-3 weeks... theyve been lasting from just over a month to just a few days. I have some questions Is it possible that the 240z alternator is just not powerful enough to power the ZXT EFI and fuel pump? Maybe it's just too much of a drain? I had asked about what mods are necessary to install a later ZX alternator into the 240, but no one replied I know it's not just a bolt in replacement... the ZX alternators are internally regulated, and require some sort of different wiring setup. Is it possible that NOT having my fuel pump running of a relay could somehow be the problem? It doesn't make sense to me, but a friend of mine suggested that could be it. If it's not either of these things, where do I start to troubleshoot?? If it's not something I can figure out, then the car will go back to being parked for a while... I just cant afford to pay anyone to work on my car anymore right now.... I'm getting that feeling of wanting to sell it again... this is just really way more than I bargained for... At least I could get enough for it now with the rebuilt engine to put a nice down on a new car.... Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 16, 2003 Share Posted November 16, 2003 I had a friend wire up my Maxima alternator, 80 amp internally regulated. It took him an hour or so. I am a wiring moron at best, but any automotive wiring shop should be able to take care of it for you. They bolt right on, so mounting is not an issue. Jon Quote Link to comment Share on other sites More sharing options...
Ivan280zt Posted November 16, 2003 Share Posted November 16, 2003 Here is the link on how to do external to internal conversion http://zcarcreations.com/howto/voltreg.htm very simple even i figured it out . right now i use i belive 70amp alternator from zx and its doing just fine but before that i have used 120amp (maybe few amps more or less) from early 90's patfinder and holly crap was that thing awesome headlights were so bright and every time i turned big electric fan there would be no voltage drop whatsoever only thing that i had to do to make patfinder alternator work was to use 280z pulley (same as 240/260???) and just slightlly enlarge the inlet hole on 280z pulley. i had to use that pulley because patfinder uses different style belt. hope that helps out some. Ivan Quote Link to comment Share on other sites More sharing options...
Guest d9 Posted November 16, 2003 Share Posted November 16, 2003 Do yourself a favor and get an OEM. I had an '80 ZX with an alternator that had failed. I took the old one to Advance Auto Parts and got a replacement. Installed it and.... no deal. Wouldn't work. I had the factory manual and a digital meter and started troubleshooting. Nothing was wrong. As strange as it seemed the new alternator was bad.... so I took it back. They put it on their bench and tested it. It worked fine... but offered me another one just in case. I took it home and installed it. Same thing. Nothing wrong but no charge. Took it back and got a 3rd one. Took it home with the same results. I had it towed to the closest Nissan dealer and slid the key under the door with a note. Please troubleshoot and advise. They called me and said "it's fixed". I asked what the problem was, "it was the alternator". I said... I don't want to doubt you but I don't believe you. Can I speak with the mechanic that did the repair? He said sure. The mech assured me that it was the alternator that was bad and that it was fixed. So I had my girlfriend (at the time) drive me back to Dayton.... 45 minutes away... absolutely sure that it was not fixed. I popped the hood and looked for myself and saw the OEM alternator installed. Still sure it was not the problem.... I refused to pay until I started it and saw that it was charging. I ate a big 'ole crow and paid the man. So back to the original statement.... "Do yourself a favor and get an OEM". d9 Quote Link to comment Share on other sites More sharing options...
Guest szlash280z Posted November 17, 2003 Share Posted November 17, 2003 I want to go with the GM alternator conversion. Quote Link to comment Share on other sites More sharing options...
fl327 Posted November 17, 2003 Share Posted November 17, 2003 I second the gm alternator, nice units, definitely on my list of things to do, since its known you can get a alternator for a camaro anywhere. I think you are blowing alternators out because it has to work so very hard, 40amps doing a job Nissan said 70amp should be doing. OEM alternators are great, but I have also had great luck with NAPA as far as alternators go, I have a year on my current zxt alternator and its been good to me. Just get the OEM specified alternator for your car or go one better and you should be ok. Quote Link to comment Share on other sites More sharing options...
240hoke Posted November 17, 2003 Share Posted November 17, 2003 I think the Maxima conversion is the way to go, in the end it will cost the same as the GM conversion, and in my opinion look alot cleaner. i believe they make a 125 amp one? correct me if im wrong. I was using a northstar caddy alternator, with a bracket that i made. this worked really good and didnt have any issues until my bracket broke at the drag strip im using a 280zxt alternator now and havent had any problems, looks alot better than the big Gm one anyway -Austin Quote Link to comment Share on other sites More sharing options...
Sean73 Posted November 17, 2003 Share Posted November 17, 2003 Did you replace the voltage regulator? That's probably what's causing the shaky needle. My charging system never worked right until I switched to an internally regulated alternator. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 17, 2003 Share Posted November 17, 2003 I did replace the external regulator with a new unit. The one that was on the car before looked like it was the stock unit, 30+ years old... oh and then I read this line on that conversion link: "The aftermarket, solid state external regulators never seem to work right (one actually caused my clock to smoke)" grreeeeeeeeeaaat wonder if that's the problem??? I followed that link for the wiring instructions for internally regulated... I'll be the first to admit that I'm really not so good with wiring and electrical stuff. One thing I can say is that the connectors shown in the pics are definately different than the ones on my car... I dont think this is something I should attempt to do myself, at least, not unless I can find instructions specifically for wiring an internally regulated unit into the 240 (that link seems to be for the 280). I'll take a look at it today though and see if the wire colors match the 240's wires. I had no idea the stock 240 regulator was only 40 amps but I will say that it seemed to be working fine, the amp gauge showed right about where it was supposed to be, up until this starts happening and the needle get's all crazy... *shrug* but I can see how running the turbo efi and stuff on it just might be too much draw for it. But at the same time... is no one else here running the 240 alt with a turbo swap?? The only reason I ask is... I'm not 100% convinced that switching to a later alt will solve the problem and make them stop burning out. Unless... well I guess the chances are higher than I thought, that maybe the alternators I've been getting were bad to begin with. For FOUR of them to go out in two months though, and only two of them were from auto zone, again, makes me think something else is wrong. I'm really just getting tired of chasing this problem.... Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 17, 2003 Share Posted November 17, 2003 Heh I just called around looking for factory nissan alternator... I had no idea they'd be so cheap. I'm so used to factory stuff being like 3x the cost of non factory... unfortunately, 3 nissan dealerships I called say there is no longer a part # listing for the external voltage regulat so... this may all be a moot point. If ANYONE has wired an internally regulated alternator specifically into a 240, please please please give details or some kinda link to see how to do it, or clarify if the link to the 280 wiring instructions above will apply? Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 17, 2003 Share Posted November 17, 2003 Another question: What year did the Z alternators go from externally to internally regulated? Would a later year externally regulated alternator provide more amps and if so would it be worth it to just try one of those before doing any wiring stuff to adapt an internally regulated one? Quote Link to comment Share on other sites More sharing options...
David K Posted November 17, 2003 Share Posted November 17, 2003 I have a GM alternator that has a v belt pulley and nearly bolts up to the stock L mounts. I have no idea what its from, just that is is GM and i would like to use it. Quote Link to comment Share on other sites More sharing options...
Sean73 Posted November 17, 2003 Share Posted November 17, 2003 I converted to internally regulated with the instructions in the technical articles at Zhome.com. It's only a few wires, and a diode. There's not much to it. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 17, 2003 Share Posted November 17, 2003 Kewl I'll check there. Someone recommended to me that I stay with externally regulated, but get an alternator from a later, '75 or '76 alternator, which supposedly puts out more amps. Well called around to reference the part #s and it turns out the '72 and '75-76 have the same part # listed... so much for that. There is mention of a higher output model in the Haynes manual but no one seems to carry any different part. I'll check Zhome right now and try to find the writeup Sean Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 17, 2003 Share Posted November 17, 2003 Okay now the wiring directions make sense looks pretty simple after all Sean73 or anyone whose done this, I have one question, regarding that diode. The writeups you guys mentioned only mention the diode for use with the 240 or 260z, but not for the 280. I wonder if this has something to do with the fact that the 240 and 260 are carbuerated?? Since I"m running a later, fuel injected '81 ZX motor, I'm wondering if this means I dont need the diode? I'm wondering if the diode only keeps power from running to the ignition, which, in the case of the 240 and 260, as long as their is spark the car will keep running. But in the case of the EFI ZX, turning the key will turn the fuel injection off, so even if power is still getting to the ignition, the car can't run. I may try w/o the diode first to see what happens. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 18, 2003 Share Posted November 18, 2003 Got the turbo alternator in, bridged the four connections as per the instructions at Zhome.com, fired her up and all seems well. The amps were reading a bit too high and fluctuating a lot with engine revs, but I think that's because the battery was probably getting pretty strained from driving with the other alternator crapping out. If I remember right it's done this every time one has gone bad and I've replaced it. And the needle moved a LOT when I would turn the lights on and off... about 3 or 4 needle widths... whereas before it would settle at the same spot after turning the lights on... so I'm not sure what to think. Oh... and it turns out... I DO need the diode... went to turn the car off and sure enough it keeps running, though the fuel pump does shut off. I had to disconnect the alt to get it to stop. So tommorow I'll pick up the diode. I dont know what was going on with the other alt but man when I got home and opened the hood there was a very very strong coppery burning smell... that electrical smell... coming from the alternator (the 240 alt). And another thing... when I was on my way home, my dash lights went out (AGAIN!!!!!) so I checked the fuse and this time it looked fine (??) took it out and replaced it anyways and sure enough the lights come back on... now, it has done this before, and when it was doing it and I replaced the fuse that time it would blow out immediately (and I tried several times). Now, I can replace the fuse and turn the lights on, and the fuse wont blow, BUT the LEFT side terminal that it snaps into slowly gets really really hot. The plastic around that terminal is a little deformed. So, just for the heck of it I decided to try a lower rated fuse just to see if it was overloading, but not enough to blow the 20A, so I went from a 20A to a 10A, and it still wont blow, just get's really hot. I wonder if this has something to do with the amp needle moving so much when I turn the lights on? Whatever it is... it means I"m still far from done with this thing and for the time being still dont have a driveable car Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted November 18, 2003 Share Posted November 18, 2003 i am running a 81-83 zxt alt in my 77 with a 81 zxt engine.the 77 alt wouldnt run the a/c and lights at night-its hot in summer here.there are wires at the old regulator that you have to id with a test light.the 2 original field and stator wires are removed.you are left with 2 wires.1 is for the charge light in volt meter.1 is hot from key to trigger alt.these 2 wire got to new alternator.i hooked up the big hot lead and started car up.i touched the key wire to the s and l terminals.the l is for the red warning light and the s is for turning on . Quote Link to comment Share on other sites More sharing options...
Sean73 Posted November 18, 2003 Share Posted November 18, 2003 Never install a new alternator on a weak battery! Charge the battery first before you do anything, or you'll fry your new alternator. Better yet, have your battery tested by sears or autozone. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 18, 2003 Share Posted November 18, 2003 It's a new battery, only about a month old, and I wouldn't have thought the battery was weak, as the old alternator was still charging it before I swapped it out. I think it was only a little lower than usual. Anyways the alternator is used... I'm not counting on it lasting long, but thank you for the tip I'll take the battery to get it charged today. Autozone said they would let me upgrade from the 240 to the ZX alternator, still covered under warranty. This swap is really easy... all I had to do was make to bridge wires using short pieces of wire with a male spade connector at each end. The spade connectors plug right in to connector of the wiring harness, and the diode can be wired in to one of those jumper wires, as opposed to trying to put it in the wire going to the alternator. Easy breezy... wish I'd known it would be so simple Now I just gotta figure out why my fuse is getting so hot... Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 18, 2003 Share Posted November 18, 2003 Sean, I'm stuck on one more thing here... Once again, I'm looking at two different websites giving two different directions on how to do this thing... The zcarcreations write up says to do this: "The cathode end of the diode (end with a white stripe) should be connected to the switched 12V connection. The anode end of the diode should be connected to the "L" terminal." and the Zhome.com writeup says to do the opposite: "You have to connect the cathode of the diode (identified by a stripe on that end of the diode) to the "L" terminal and the anode (other end of the diode) to the wire that previously went to the "L" terminal" which way did you do it??? I mean... if I install it the wrong way it will be very easy to turn it around, but how will I know if it's in there wrong or not? I dont want to fry anything! Quote Link to comment Share on other sites More sharing options...
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