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I'm in the process of making wire harness changes that include upgrades and additions that will increase the total current requirement from the alternator/battery. Ultimately, besides wire gauge changes, the alternator will need to be upgraded. For this calculation, I started with the belief that winter and summer might be very different. Turns out, maybe not so much. Loads are computed at minimum charging voltage: 13.5 (arguably). Lighting current is based on using incandescent bulbs which also will see "persistent" and "transient" use. The persistent load comes out to about 17A, while transients total around 16A. I took a WAG and chose 25A for both. Some other transient loads, such as power windows, are not included. Audio equipment is not included. The highest load case in this example is 134A. If you believe in safety factor, and I most certainly do, it looks like I'll need at least a 150A alternator. Has anyone successfully used an alternator rated in the 150 - 200A range?

Had a bit of excitement. After four years got my 1970 240Z fully restored and on the road. After about 1 hour of driving had smoke in the cab from insulation burning on one of the primary power wires under the dash (see photo). I repaired the wire and added a new female spade connector and then proceeded to clean the connectors under the dash by the passenger kick panel (second photo) as well. I then reconnected the wire and ran the car and held the wire with my hand and noted it becoming hot. Tested resistance on the wires and they seem fine. Also, noted that when I turn on any item, lights, dome light, brake light, etc. the fuse clips related to that item also get warm. I checked all the fuses and then pulled them all except for the ignition fuse and experienced the same result; warm/hot charging wire. The primary wire from the alternator does not get hot nor does the wire to the starter/battery. At this point I am stumped and need some advise please.

Hi everyone, I own a Hybrid 260Z (with a 280ZX turbo powertrain) with some issues that I'm trying to clear up. I believe the electrical harnesses are a mix of 260Z, 280Z and maybe 280zx so I can't look in a service manual to figure things out (I do have all 3 manuals though). I need to understand what's going on, and I need some help with this. There are a few issues I want to resolve, so I'm taking a baby steps approach, a little at a time to avoid being discouraged by the whole thing. First step, replacing the fuse links with some Maxi fuses. I'm not sure the wires that were in the fuse link holders were fuse links, so I'm replacing them with something cleaner looking and newer. I've read up on a few posts online about such a replacement. From my understanding, the fuse links were fed by 4 white wires, while the white with a red striped wires go on to other circuits after the fusible links. The white wires have been replaced by a 4 gauge cable going from my + battery terminal to my starter, then feeding into my maxi fuse holder. I have the 4 white with a red stripe wires to connect. The first one splits into 2, with one wire seemingly going through the firewall toward the fuse panel on the passenger side. The other splits into 2 again, with one wire going to the alternator on a T-shaped connector and the other to the alternator output. Doest this make sense? The gauge seems awful small, especially for the alternator output. Thanks in advance for helping me figure things out, one wire at a time if necessary. Gilles Lajoie

Hello Z Community, I am coming back in hopes to revive my Datsun once again. Before I jump back in I want to give a back story to this situation. Car has been sitting in garage for the past 9 months. I charged the battery in hopes to get it cranking and starting again. After some attempts of failure, I left the car in the ignition and turned to "on" (where you hear the buzzing). Fire ensued. The fusible link for the Alternator/Ignition Relay link caught fire. (diagram below) I replaced the fusible links and charged the battery. It can be seen below (black). (You can see some of the fire aftermath at the bottom of the fusible link. It is like a pimple) Car started to idle rough but then idled perfectly. However, it can not hold its charge. I would attempt to drive the car the next day, but it would struggle to crank. So i made sure I charged the battery again and drove the car around. Battery is new. From previous attempts(previous thread), we did test the alternator and did get a charge. I wanted to ask the community, what is withholding my car from holding its charge? I do want to mention, there is an aftermarket radio that was installed in the vehicle by the previous owner. A friend suggested that improper installation caused a short circuit and was the leading cause of the fire. I pulled the radio today and found copper(or some metal exposed). Would this have instigated any issues to what has happened to me? (pic Below)

I find myself reaching out to this awesome community once again. I have a 1974.5 Datsun 260z (Oct 1974 build date). Two weeks ago all was right with the world. I'd had a nice afternoon of driving the Z. I stopped to fill up the gas tank and when I started the car back up none of my gauges were working. Nothing but the speedometer (it's a mechanical connection). Fast forward to this Saturday an my battery alone will not start the car. I get a jump start and try to make it home. It's night and I have my headlights on. By the time I make it approximately 10 miles to my home my headlights are barely visible. Here are my questions. Do you think that the gauge issue is connected to the battery/alternator issue? based on the photos below, do you think my alternator is the original (or a stock replacement) or has it been upgraded to a newer internal voltage regulator type alternator? I have charged the battery and the car starts and runs fine for the short drive I had today. I'd appreciate your guidance on solving this issue. Thanks!

Hello, I have searched previous threads and am not coming up with an answer. I have no power at the signal wire from the voltage regulator to the altenator. I have replaced the altenator, then the battery, then I thought maybe I got a bad altenator and replaced it again after getting it bench tested, then the voltage regulator in that order. Any ideas?? Thank you in advance.

Hello Classic enthusiasts. My 1977 datsun 280z car is almost up and running. The problem is a little hard to describe. I replaced the battery and the car ran fine. I notice the car started to lose cranking power after 8ish car start ups. Around this time, the car would struggle to crank. I charged the battery right up and the cranks beautifully. At first, I thought my alternator is not charging my battery (which seems to be the case). I went through the "Alternator not powering battery" thread and could not assess my situation. I did some testings on my car with a multimeter and found some questionable data. From the battery, Trial #1 12.6v - Engine Off 13.6v - Engine Idling 11.88v - Engine Idling w/ headlights on 11.90v - Engine Idling w/ headlights on and max fan 12.90v - Engine Idling w/ lights and fans turned off Trial #2 12.42v - Engine Off 13.34v - Engine Idling 12.06v - Engine Idling w/ headlights on 12.01v - Engine Idling w/ headlights on and max fan 13.36v - Engine Idling w/ lights and fans turned off It is weird how I got different voltage readings for when car is at idle and when car is under load.. I do have to bring up that about a year ago when I was working on my car, when I tried to start my car the fusible link caught fire. Weirdly enough, it was the alternator and Relay fusible link. I replaced the link and the car starts up fine but then the car battery would not be charged by the alternator. The 1977 came with a voltage regulator that is located below the fusible link box. Would there be any chance that when the fusible link caught fire, it shorted my voltage regulator? What could be the problem being that my car is not charging while under load? If I read through a series of forums correctly, I believe that the the voltage should be around 14V while idling or underload.

I need some help with my internally regulated alternator. I have a 1976 280z that I have been restoring (full rotisserie resto-mod). The car is pretty complete mechanically. I have removed the fuel injection and fuel injector harness and control. I have removed the distributor and transistor ignition module. In their place I have triple OER Carbs and an XDI electronic ignition. I don't that either mod bears on my present problem. I have installed a 60a internally regulated alternator. I performed the wiring modifications shown here: http://atlanticz.ca/zclub/techtips/alternatorswap/index.html The problem is that it doesn't seem to work. I can start the car, but the red charge light is on and the voltage shows less than 12V on the gauge and using a multimeter. I noticed something else suspicious. When I jumper the 2/3 wires as shown in the article I linked, I can hear a relay pulling in (probably the ignition relay but I'm not sure) without the key being in. This doesn't seem right at all. I removed the jumpers and If I connect a lead directly from the battery to the "F" terminal then I can get 12.5-13V, but my charge light wont work. Can anyone lend any insight? First of all what voltage should I see off a properly charging IC alternator? How should I check it? Why do I hear that relay pulling in when jumpering the plug? Also there was a small canister (diode or a capacitor of something) on my old alternator. The wire is broken. Do I still need it with an IC alternator?

I have 3 alternators for use on the 01/70 resto I am completing. The only photos I can find are of the internally regulated units. However, I would like to disssassemble the externally regulated unit and restore it to the factory appearance. The main issue i'm having is locating the original stator band colour. The one that is in the center of the alternator and goes around the entire unit. I've seen cast-iron grey, green, and also red. This is for the externally regulated unit, which I have a new regulator for as well- so I would like to continue using this one instead of the internally regulated rebuilt unit I have. I think all 3 of the alternators I have are in good working condition, but I have to EXT regulated units that I can mix and match parts from if that's not the case. Thanks!

Hi, I have a 1973 240z, rewired the car with an EZ wire harness, and I have upgraded to a 60 amp alternator from a 280zx. I've driven the car fine until I had an issue of the alternator overcharging. The original 60 amp ended up testing bad, so I replaced it, and made sure to test the new (re-manufactured ) one I got. It tested fine, but when I installed it in the car, I hooked up a multi-meter and it was going up to 15.7 even after warming the car up, and putting load on it, including lights and an electrical fuel pump. Anybody have any idea what could cause this? Such as a wire too small going into the voltage regulator, or just an alternator that instantly went bad? Or something else? Thanks for any help!

Hi everybody, So I am wondering if anyone has used the alternator upgrade KIT from MSA? Motorsport! 60-Amp Alternator Upgrade Kit, 70-73 240Z - The Z Store! Nissan-Datsun 240Z-260Z-280Z-280ZX-300ZX(Z31/Z32)-350Z-370Z Parts Is that alternator decent, or should I really get a rebuilt-280-one? Any recommendations of an alternator that is compatible and good quality, but not too expensive? Thanks!

I have a 73 240z with no electric fuel pump. I just installed the ZXP plug and a 280zx 60amp alternator. The new alternator appears to have a cut out on the back of it. Do I need to unplug the one that was bolted to the external voltage regulator? Thanks

Made a mistake in my first post. Original and corrections shown below. Sorry for the messy post. Basically what I've found is that both of the two popular alternator conversion instructions will allow the alternator to charge, internally regulated, but they both leave loose ends for other components in the 1976 280Z. I am new to this site but thought I would share something I found out about upgrading to a 1979 ZX alternator on a 1976 280Z. Using the atlanticz.com instructions - http://www.atlanticz.ca/zclub/techtips/alternatorswap/index.html - the brake warning lamp check relay will be "hot" all the time, even with the key off, since it is spliced off of the S line to the alternator plug. I found that the slight amount of current it draws would drain my battery after a few days. According to the FSM, California cars also have an EGR cut solenoid that would also be always energized. I assume that the old mechanical voltage regulator ran the S line and/or brake check relay through the ignition circuit (I did not dig in to confirm) so this was not a problem. You can tell if you have a similar problem after the conversion, if you hear relays clicking when you reconnect the battery, with the key off. Edit 11:41 am 11/12/09 - The following is wrong, it will not let the relay work correctly. The relay needs to be energized when the motor is running/cranking, but dead when the ignition circuit is on. {{{I fixed the problem by wiring the system like zcarcreations recommends - http://www.zcarcreations.com/howto/voltreg.htm - to get the relay back on to an ignition circuit}}} I ended up splicing the brake warning lamp check relay yellow wire, which energizes the relay solenoid, to the fuel pump circuit, which has a plug in the vicinity under the passenger seat. The fuel pump only runs when the motor is running. Edit 11:41 am 11/12/09 - This part still seems right {{{, but cut the S line splice off of the circuit and wired it direct to battery + terminal.} This also lets the alternator see mostly battery charge and not the voltage after the loads on the ignition circuit. I get a smooth 14.5 volts with the S line wired direct, but was getting a jumpy over 15 for the short time I had it wired through the the ignition circuit (measured with a good voltmeter at the battery).}}} That's all I have. I enjoy the discussions and hope this helps someone out if they decide to go with an internally regulated alternator. p.s. I also found that the dash voltmeter is pretty easy to adjust using the slotted adjuster on the back of the gauge.

ok, so, am i supposed to have a charge light somewhere? I've got another alternator on now and now i am not getting power at all ever to the BW or the WB wires, and I have full time power at the White wire, key on, key off, full time 12 volts. any ideas to what is going on now?

Well, I'm sure this is a rookie mistake, but the back bolt that connects the alternator to forged piece that connect to the block vibrated out and disappeared causing the alternator to vibrate and torque, and I removed the front bolt to use a model at the parts store. I have the 8 X 25 mm bolts but... Now, I can't get either back in, as the alignment is just a bit off. So, any advice would be much appreciated. This is a 1975 280z manual transmission. Thanks very much

Dear Fellow Z Enthusiasts: I just noticed I am missing one of the through bolts on my 1975 280z alternator, the lower one of the three. These are show on page EE-16 of the FSM in figure EE-35, but the FSM doesn't give a diameter, thread length or length for the bolts. While searching another forum, I found this: The alternator has 2 12mm headed bolts at the base, and a 14mm head bolt on the adjustment bracket on top. The connections on the back are 10 and 8mm. You take the three mounting/adjustment bolts loose, take the wires off the back, and take the alternator up and out to the rear of the radiator hose towards the oil filter. Piece of cake. If this is correct, then I lost one of the 12mm bolts. As I can see this is putting tremendous pressure on the other bolts (the alternator is vibrating), I'll need to fix this right away. Can anyone provide a description so I can head to Pepboys (which is still open the day before Christmas), or is this something I must try to negotiate with my local not-very-. helpful Nissan dealer? Thanks very much for help/advice.

Hello, My alternator has an external regulator and I was wondering if i could convert it to an alternator with and internal regulator ? If I can is there a major benefit to the conversion. I have done alot of research with the local auto parts dealers and some of them say that a 1979 280zx 2+2 is suppose to have an internal regulator and some say external. I have owned the car since it was new and i am under the impression that the Factory knows best but I wanted to make sure. also Could someone give me the proper procedure for removing the alternator. My car has been garaged for the last five years and I have misplaced my Chilton's manual. Any Words of Wisdom would be Greatly Appreciated Thank You, Candice

Okay so I have a 74 260z that im looking to get as much torque and acceleration as I can. I have the basic 2.6 with dual webers on it with headers and all the emission junk removed. Ive replaced the starter, water pump, radiator fan clutch, upgraded the 4 speed to a 5 speed tranny replaced the brake booster, master cylinder, the clutch master and slave cylinder. What I have left to do is get the alternator rebuilt or replaced, replace the coil, get the headlight harness Dave makes, and replace the gas cap (the one I have doesn't seal and when i take left turns with a full tank of gas i loss my fuel) also I kinda want to upgrade to a stage 2 cam and redo the differential to get some serious torque... Unfortunately I dont know what I already have... havent checked but what I would like to know is what would upgrading the cam and changing the gear ratio do for me? and how or what do i need to do or get to achieve the most get up and go of the line?

I have a situation will the car will not charge. Started with a bouncing amp guage, thought bad alt or voltage regulator, replaced both with new. No charging. Car will start and run on just the battery, accessories work. Fusable link at starter has continuity. Took replacement Alt back to parts store got another one (5 day wait) put it on, no difference. Tried old voltage regulator with new alt, no difference. I have continuity to the W/R to the fusebox. So I have old alt and regulator and new alt and voltage regulator. AMP guage will show negative if you turn on accessories but will not show a positive charge with any combination of parts. I looked for links on this and saw that 72s may have two fusible links, and one is at the alt. I have continuity through the wire off of the back of the alt. Am I missing something really simple? Suggestions please, we have a car show next weekend, I have not been able to drive all summer. I want to be out with the car this year.

A few nights ago I was driving my 1974 260Z home and my lights started to dim, windshield wipers started to slow, and my engine began to choke. At first I thought it was just my battery. So I had my battery jumped and it wouldn't hold a charge. I automatically assumed it was my alternator after checking all my fuses. I replaced the alternator and charged my battery. I was able to drive it for about 45mins. I went home, woke up the next morning, checked the belts and such, and drove it around the block to make sure all was going smoothly. It seemed okay. Once I turned the car off and went back to start it up again it wouldn't start. Any help or advice anyone has to offer would be greatly appreciated. If there is any information I left out please let me know! Thanks in advance! -Joseph

Hi all A few days ago I upgraded the alternator on my 240Z to a 60amp Bosch model from motorsports (www.zcarparts.com). The kit somes with a cap for the wiring harness to replace where it connected to the voltage regulator that bolts onto the fender. A few interesting things came of this, and I am hoping to get some feedback from you folks. After the install, when I turned the ignition to the "on" setting, before starting the engine, I heard a rapid clicking sound coming from the right rear of the car which wasn't there before. I checked and it was the electric fuel pump making the noise. If I reinstall the older voltage regulator, the clicking goes away. I don't know if I can run this new alternator with the old regulator though, and would like feedback on that. I noticed that the adapter plug (that goes over the wiring harness when you eliminate the old voltage regulator) seems to have blown one of the links. it looks dark through the white plastic and the plastic near that looks marred. perhaps the adapter is faulty, or maybe it is intended for models that do not have the electric fuel pump? Part of what confuses me here is I thought that the 73 240Z only had a mechanical fuel pump, and that the electric fuel pump was added for the 260Z model. My production date is 6/73, so I wonder if they started doing that earlier. The electric fuel pump looks like a stock piece and looks like it is the original, as it is worn and rusted, and fuel seems to be leaking from the bottom. So one question is whether this is the stock setup for a June production 73 240Z, and whether I should replace the electric fuel pump or just eliminate it altogether. The fact that the wiring looks like it is original and pat of the harness and the pump looks stock leads me to believe it is the stock setup and should be replaced, but I am looking for confirmation.

Hello, on my '72 I found out that I've got a bad alternator, so i've picked up a rebuilt replacement, the only problem... the dealer installed york air compressor. The problem I have is how to remove the old one and get the replacement in place. From the back i've got the support brace from the bottom of the compressor to the motor mount and in the front its the radiatior, etc. Now about the A/C system... it's not currently hooked up, I'm missing the idler pulley, but the system appears fine, i'm giving it a 50/50 shot at working, no oil seeping from the compressor and all is still intact. The switch under the dash still engages the clutch... so I don't want to remove the A/C untill I am shure its junk. What is the best way to remove the old alternator??? Thanks, Todd

I did the alternator upgrade on my 1971 240z which eliminates the Voltage Regulator. The upgrade is on this site from Bambikiller and is posted on another site with pictures. The problem, with the Light switch on I have no side lights or brake lights until the motor is running. Yes I did the Headlight Switch cleanout procedure and its beautiful in there now. Any ideas??