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Hi. Lance here. I finally got around to rewire my 1971 240z. It had a L28 and a faulty wiring and I'm very confused. So, I found a small metal box on the back of my speedo. It have a Yellow and a Yellow/black wire coming out and a red wire that hooks up with the speedo. I teared apart the old wiring and found the yellow one is connected to the IGN Black/White wire using some sketchy electrical tape, and the Y/B one is routed all the way to 4 big 2x5 connector that connects to the engine bay harness. I'm guessing this is a mix matched setup? Voltage regulator is not wired either. Since I'm rewiring the whole thing I just need to know what the heck is this small box. It outputs red about 11.6 volt when battery is connected via Y, and nothing at Y/B. I searched online and found this image of a 260z gauge that appears to have the identical box. It seems those green wires are the Y and Y/B on mine. I did some research online and found out nothing. Have anyone got a idea of what it does? I'm testing the gauges and the speedo and fuel gauge is not working.

So the headlights on my late model 260z are not working on brights or regular. The brights blue rectangle in the tach does not light up either. This car has a newer headlight switch and turn-signal switch and I think the headlight harness upgrade as well. It has worked in the past until last night when I was out late then expected and tried to turn them on...that was fun Does this car have a headlight relay(s). Fuse is ok. My electrical skill level weak so please keep explanations very simple. As always I appreciate any help

Can anyone tell me what these things are on a 1974 late model 260z Unknown item 1 is on the passenger side mounted above the frame rail.(silver box mounting screws on top, might have been black in the past) Unknown item 2 (rectangle metal box with wires going to it) is under the black cover on the passenger side in front of the battery on the fender well. It is under the black cover on the back side (towards back of car). item 3 is on the opposite side of item 2 under the black cover towards the front of the car.(smaller metal box with wires connected) Item 4 (the silver box on the firewall) is on the firewall on the passenger side I am trying to find out what they are and then find replacements so I can add them to my back up parts in case they fail. Thanks

I have decided to rewire my aging wiring loom and upgrade it to execute all the little upgrades I have in mind. I am by no means an electrical master, but I know the importance even our 70's cars need. My plans for my '74 260z is to wire tuck, hide the wires in the engine bay to be nearly nonextant, and to also include motor sport techniques to make quality upgrades. All wires will be replaced by Tefzel wire and Raychem heat shrink. the point is to make a bulletproof wire loom and to have fun working on this project and making it special. Now for everyone's benefit i will be updating this with all the stock wiring specs as they are on my car with what ever has happened to this car in the past 45 years. I will come up with a Key to understand the small database i am trying to start. the end goal is to help others in their wiring projects. the github link: https://github.com/youztheclue/S30-Spec.git KEY: System name: Subsection Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Hopefully I can create something useful here: and I encourage others to comment, tips, hints, hidden secrets and their own data and I will add it to my data set. Update: I now have the entire front half from the firewall to bumper measured and mapped out. Will be updating soon. Lights: Exterior Headlights Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Turn Signals Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Taillights Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Brake Lights Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Lights: Interior Dash Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Map Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Wipers: Motor Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Fluid Pump Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Engine: Starting Fuel Pump Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Ignition Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Coil Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Electric Choke Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Engine: Constant for running Electric Fan(s) Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Alternator Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Fuel Injection Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Ignition Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Dash/Instruments: Gauges Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Switches Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Luxury: Heater/Fan Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size A/C Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Radio Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Power Windows Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size Power Door Locks Detailed description to-from/Route #gauge(American), Stock color, My new color for reference Stock length, New route with reasons for change, length of heat shrink for specific subsection Expected electrical load, name of oe connector/number of wires, new connector style and size

Noticed my brake lights weren't working on my 1972 240z. 1. Replaced the brake light switch, still not working. 2. Turn signals, lights, hazard lights all working and blinking. 3. Used a meter to test both new brake light switch, and wires leading to switch. power seems to be going to switch, and new switch doesn't seem to be faulty. Not really sure where to go from here. I've never really worked on cars before, so my mechanical/electrical expertise is minimal. I just successfully upgraded to an electronic ignition and new coil, and that's the most in depth thing I've ever done working on a car ( I was proud of myself for getting it working, and not having something explode or catch on fire haha). Any ideas or help would be greatly appreciated!

Hey guys, I'm brand new on here. I have a 75 280, and I'm having some issues. As most know, datsun is really weird about switching up their transistor ign modules throughout the years. Mine came with the E12-06, but I had a buddy who had a E12-27 that he'd sell me for cheap, so I grabbed it. However I've run into an issue. The 06 is a 7 pin (non cali), and the 27 is 5 pin, missing a brown and white wire. From what I've seen, the brown is a ground of sorts, but the white goes through the water temp relay to the water temp sensor (I'm assuming to advance/ retard turning when cold or at O.T.) My question is what should I do with the white wire? I may have to manually flip the relay somehow with a switch, but I might not have to. Any input will help!

My 1974 260z haa uad some difficulty starting. I read up and found the engine has a reset button so I tried this and it would finally turn over, after i had replaced starter and ignition switch, but every wire in the ignition system got so hot they started to smoke... I'm not going to pretend es and I have any idea what's happening. The car has an electrical points upgrade, and an ignition coil from a 240. Currently not messing with it for fear of burning all my wires completely. Please help!

The electrical harness on my Z is in wretched shape. P.O. cut through and spliced too much to name. I have no brake lights. And yes I have read an excellent no brake lights thread. I have one working turn signal (left), no hazards. I just reattached the hazard switch connector which is what brought the one turn signal online. Im thinking it’s the multifunction switch. But it’s hard to say there is so much electrical terror in my car. Maybe it’s the brake pedal switch. The most likely culprit is abuse by a PO. Any tips or advice?

well, after weeks of working on it, i'm finally done. and you can reap the benefits of all my work! below i've made available my new, full-color version of the 1976 280z wiring diagram. it is vector-based, so it can be blown up as big as you'd like without losing legibility. the text is copyable and searchable. i will warn you, i'm 110% sure that there are errors. you get a gold star if you point them out to me. a wire or object in hot pink denotes that i'm not sure of the true color of the item. i'll post updated versions on this thread as needed, so look at the most recent reply for the newest download. enjoy! download here: http://sridout.com/datsun/76circuit_COLOR v.1 edit: i thought i'd add an illustration that i just finished for Tim280z of his car. take a look at the thumb below...

I have had my z for a couple of months (1976 280z) had some trouble with the ignition relay at first (accessories did not work) but got them working in the end. Started driving it 2 weeks ago no problems everything worked fine. Then last week I went to start it and it had no spark so after messing with the ignition relay and coil for a bit I found one of the fuseable links was bad (the one that goes to the lights, whippers and washer motor controls.) I replaced it hooked up every thing tured the key, and nothing worked then I heard a relay click and a fizz frying type sound comming from the passanger side didnt smell any thing. I took out the igniton relay and took it apart and all the wiring harness conectors. Checked the relay and filed the contacts and hooked it back up and still nothing. If I turn the lights on the voltage gauge pegs below 12 volts and the lights dont turn on the head lights will on the second click. I tried unhooking all the wires connecting to that control arm and still nothing when i tured the key. I could still hear the clock ticking aswell. I am thinking about taking the dash out I also need to replace the heater core, do some rust work on the fire wall and under the battery, and carpet aswell as some lights and what not behide the dash. Thank you.

I'm finishing up the wiring as I near the end of the restoration of my '76 280z. There is a single black wire with a spade connector on the ignition switch. Any help on where it connects? You guys have been a great resource so far! Thanks!

I have a 1972 240z, and the guy I bought it from got a viper security system and a beefy sound system wired in (very poorly might I add). I need to rewire a lot of the engine bay and the wiring diagrams available are not helping, a lot of wires are spliced and replaced that don't match up or are just taped off and lead nowhere. If anybody has a diagram of all the 10 pin connectors that are located underneath the passenger side of the dashboard it would help a lot, or if anybody has any self made diagrams that are at all related to engine bay wiring please post them, anything might help me out.

I recently installed the Crane xr3000 and used the 14 gauge wire - per the Crane instructions. However my tach is not steady and it will drop sometimes between shifts. It just generally works poorly. I have heard of a fix for this - anyone know what it is.

Could someone tell me the wiring color to color on the combo switch from the switch to the dash 9 pin connector. I had my switch redone and my 9 pin on the dash side was melted I had to put the wires into a new connector on the dash side and I am not sure if I got if right.

I have a short or something going on that when I pres the brake pedal the sidemarker lights and the dash lights come on in addition to the rear brake lights. Also when I have my headlights on the turn signal for the left signal lights up ...Anybody have an issue like this and how did you fix it. Thanks

This little switch is located on the passenger side of my 73 on the far right, the wiring looks new, but I dont have a battery yet nor have I tried to hook one up to the ancient leads to see what it does..but it doesn't quite look stock. Does anyone have any idea what this is for? Additionally, that choke looking pull, there are about 3 of them on the driver side if I remember correctly. Have no idea what those are for either. I've never heard anyone mention these bits on the inside of Z cars nor have I seen them, or I wouldn't be asking.

Oh so wise Z community! I need your assistance desperately! I have a short... Somewhere! I currently have, running lights at all. I also have no dash lights, marker lights, tail lights, or engine light. I believe the dome light is also not working. What I do have is headlights, turn signals, brake lights, map light, and radio. When I change the fuse (tried 3 times) it immediately flashes and burns.. So much so that I burned my finger. Oh wise ones! You direction and help is very needed! Thanks much! Kira The lil z lady

Oh so wise Z community! I need your assistance desperately! I have a short... Somewhere! I currently have, running lights a all at night, I also have no dash lights, marker lights, tail lights, or engine light. I believe the dome light is also not working. What I do have is headlights, turn signals, brake lights, map light, and radio. When I change the fuse (tried 3 times) it immediately flashes and burns.. So much so that I burned my finger. Oh wise ones! You direction and help is very needed! Thanks much! Kira The lil z lady

Oh so wise Z community! I need your assistance desperately! I have a short... Somewhere! I currently have, running lights a all at night, I also have no dash lights, marker lights, tail lights, or engine light. I believe the dome light is also not working. What I do have is headlights, turn signals, brake lights, map light, and radio. When I change the fuse (tried 3 times) it immediately flashes and burns.. So much so that I burned my finger. Oh wise ones! You direction and help is very needed! Thanks much! Kira The lil z lady

For some background I have a '71 Datsun 240z and have made a few modifications to it so far - replace solenoid, new plug wires, new spark plugs, cleaned the carbs. it worked fine until the engine sat for awhile. I put on a new valve cover and a new exhaust. since then I can't get the thing to start. Now every time I try to start it it'll sound for about 2 seconds like its going off of starter fluid then cut out, totally unresponsive to the throttle. it'll only do this for the first go around and after that i can crank for days and nothing happens. This makes me think its a fuel/spark issue because its getting flooded so it only happens the first time, however, since this problem started happening i've tried the following. - checked the fuel to the carbs. i took off the hose and cranked the engine and got a lot of fuel coming out - i made sure that the plug wires corresponded correctly with TDC and that the firing order was all correct - got a new battery - got new spark plugs - cranked it with a $^!# ton of start fluid. I havent adjusted the timing but i'm guessing it should be fine if it was fine before and I never took out the distributor. any suggestions would be greatly appreciated.

Just finished a complete engine rebuild on my 1975 Datsun 280z (I named her Bonnie) a few days ago. I've owned Bonnie since 11/1/2015, just 6 months now, and began the rebuild the end of November. When I tried to start it, I have absolutely no power in the car, no lights inside, no headlights, no clicking in the ignition, nothing? Hoping I didn't kill Bonnie. Here is what I've done so far; I've cleaned and checked the battery and terminals, all new terminals. Checked for power from positive, the only power I have is to the starter, no power to the alternator or the ignition. I've checked the grounds, all are good, the two bolted to the frame and the one to the back of the starter. Needless to say, I'm both stumped and frustrated. I can post pics of anything anyone needs, I appreciate your help. P.S.- Bonnie ran very well when I bought her, all lights worked, started every time, no problems. Just a tired engine. Help??!! Troy

I have a 73 240Z which I converted a few years back from points to a Crane 700 electronic ignition. Ever since I did the conversion I have had difficulty starting the car when it is cold and the engine easily floods. The spark appears weak while cranking and often needs a shot of starter fluid to turn over. The real problem is that it generally only starts after I stop cranking the starter. As soon as I let off the key to stop the starter from cranking is when it generally starts. It seems like the starter is drawing too much current but I'm fairly convinced that it has something to do with how I have the electronic ignition wired as this was never a problem before the conversion. The problem doesn't get better if trying to jump start from a running vehicle. Any suggestions?

Hi all: I searched here for the answer, and I Googled a bit for a source. But no luck so far, other than Ebay, which has connectors that don't look the same as mine. I noticed on my '77 (that I just bought) that the AFM connector does not seem to have any retaining means in the AFM. If I unbolt the AFM, the connector falls out as soon as I move it. I'm concerned the connector will fall out while driving. Is there a source for a replacement connector, aside from getting an entire harness? I can't even tell what is supposed to retain it. But I assume this is not an uncommon issue. Before I shell out $300+ for a harness, I'll explore a home-made solution. But I'd rather replace the plug (or whatever retains it if that can be retrofitted). Thanks in advance, John.

Completed my installation of a fuse block to replace the ageing fusible links. Used the same Mini ANL block that Mike W used in his 260, except purchased the 4 fused output block. One 80A ANL for the alternator feed back, and three 50A for the other circuits were the fuses I used. This model has 2 inputs so I will eventually run another cable from the unused port to a inexpensive 2 output small fuse block without the digital bling for the FI links. The display has 4 led's for the fuse status, and the system volts / current. The display cycles between volts & amps about every 10 seconds and shuts itself off in 90 seconds if there is no circuit activity. A good thing, I was worried it would stay lit up all the time & was getting ready to put a small toggle switch on the ground wire for the display to kill it. Worked out well. Fairly accurate, shows my battery to be 12.9 volts when the car is off. Shows my parking / dash lights are 3 to 4 amps when on.

Hi Guys! I need advice on my left rear turn signal diagnostic. The left rear turn signal quit working. All the bulbs are fine. The left front signal works fine. Both right turn signals front and rear work fine. ALL the hazards work including the left rear. BOTH rear brake lights work. HOWEVER, When the brakes are applied the left brake light goes out when the left turn signal is activated and there is no flashing signal. With the right turn signal activated and the brakes applied, the right signal flashes normally over riding the brake light. I read a couple of threads and my diagnosis is; - Turn Signal Flasher is ok - Hazard Flasher is ok - Brake over ride switch is ok I read a thread that stated the column switch as individual contacts for the front signal and rear signal. My gut tells me the switch is the culprit, in particular the rear signal contact. Thoughts? Advice? Comments? Thanks in advance!