FSM Wiring Diagram inaccuracies?

[Bob_D]

I've done quite a bit of searching, but have not come up with an answer to this... I have a 73 240, I have the factory service manual, as well as the downloadable version that someone was nice enough to post on a different site. Here's my questions: The FSM wiring diagram for a car with a manual transmission (page BE-5) shows Fog Lamps, which I understand was not a U.S. option, so I am not surprised to find no wiring for them in my car, but the diagram also shows "step lamps" (right and left hand), which I can't find any evidence of my car having. I am assuming that these were not a U.S. thing either.  I am wondering what else this wiring diagram is showing me that does not exist on a US spec car. Does anyone have any insight on this? Here's another thing, I am trying to decipher what the diagram is showing me for the combo switch/turn signal switch. My manual is a little blurry on some parts of that "chart". I have redrawn it (see attached graphic) with the questionable bits in red, and I put blue X in place of the word "off" (since the word was too long to fit in my graphic). Also, does anyone have any idea what the numbers in the left column are for. I'm thinking the letters in the second-to-the-left column must relate to things like H=high, L=low, I-intermittent, etc. but some of those letters are not making sense to me.

 

With all the electrical topics discussed on this site I'm kind of surprised that there isn't a dedicated electrical section!

[Domzs]

I think numbers indicate pin ( wire ) locations in the connector , most connectors have numbers and letters . Letters are a little confusing , like " E " . H = high and E = earth ( ground ) , just a guess .

[Bob_D]

Hi Dom, thanks for the reply. I agree that the numbers could relate to connectors, but in looking at the connectors on the turn signal/high beam switch even using a magnifying glass, I don't see any numbers on the connectors themselves. Besides, some of those numbers are associated with a wire that just has a single "bullet" style connector and isn't part of a larger multi-pin connector. Still, perhaps it relates to the other end... those 10-pin connectors in the passenger area? As far as the letters go... E=earth makes sense since this is a black wire. I'm really stumped on the M and D on the turn signal/high beam switch. And if anyone can correct or confirm the HIGH PUSH PUSH in red in the jpeg That would be a big help.

[Domzs]

Not all connectors have numbers and/or letters . If you are looking at a wiring diagram , those numbers/letters is a way to ID connector or connector cavity ( pin terminal ) . 

[Tony D]

They are pin designations, there  was a section somewhere to show you how to determine pin position... something using the locating tab up, then top left to right, then next lower row left to right, etc....

That is a nice redraw. Definitely something worthwhile to be sure! I got a real manual and they're blurry!

[Bob_D]

Hey guys, I could buy the numbers=pins if the numbers and numbers-of-pins agree. I just don't see how you could have a pin 11 on a 9 pin connector. In my 30 years as a design draftsman (many of them doing schematic work), I have never seen electrical connectors have pin numbers that were totally off from the pin count. I have seen connectors use letters, numbers, and combinations of letters and numbers, but never arbitrary numbers. According to the wiring diagram and the body harness drawings, the largest connectors we have in these cars only have 10 pins (at least on the 240). Therefore there should not be any "number 11" or higher (the way I see it). That's why I put the shout out for help, because what's in the FSM just isn't making sense to me. Perhaps I am trying to read too much into these numbers, and they were just meant for some sort of internal Nissan technical document, and not for us "owners". Page BE-19 in my manual shows the windshield wiper/washer schematic in more detail, and there are numbers (1, 2, 3) and letters (W, L, H, E, B, P) that I can see corresponding to the attachment in my original post. (W= Wash, L=Low, H=High, E=Earth (ground))... But what do B and P stand for ?

 

Then there is the turn signal/high beam switch. For the turn signal column, I figure L=Left, N=Neutral (centered), R=Right.

 

The "DIMM" column is for the high beams, I am thinking M=Maximum (high beams on), D=Drive (normal headlights). This is based on following the RW wire that is associated with M up to the speedometer where it looks like it is connected to a lamp (high beam indicator?). I think the "PASS" column may be referring to a JDM or Euro spec car that would have a momentary "flash to pass" feature found on newer cars, but since our US spec cars only have a pull-click-on/pull-click-off high beam switch we don't have any dots in this column. (But if they were going to do a U.S. specific wiring diagram why didn't they remove the fog lamps and step lamps from the diagram? ) That last column that I have labeled "HIGH" in red I now think should be "HORN". If you follow that GB wire it ends at the horn relay. Seeing as the physical switch does include the horn conductor that contacts the center pad, I guess I can see why they included the horn into this diagram.

 

Hey Tony, I found in my FSM the wiring diagram for the automatic equipped car is less blurry than the one for the manual transmission. Perhaps yours is the same? I hope I didn't come across sounding like an argumentative SOB. That was not my intent! I really appreciate all those who take the time to read the post and offer suggestions. So Tony and Dom, thank you very much for your input. Perhaps we can get this sorted out so that when others browse this topic looking for answers we can have something solid for folks to refer to.

[Tony D]

Terminal 1 is always the high tension coil lead in Europe.

86 a switched relay 86a an aux contact set of that same relay, 15 the ignition or some such logic...

Outside of Europe, it doesn't mean anything!
None of this is standardised in any way. As I said, in the FSM there is a legend that explains Pin Numbering.

 

The biggest problem anybody has is using their prior conceptions to apply to another system which works on logic that is totally different. Generally, there is absolutely no correlation, and the best way is to flush what you know and start over with the FSM and what they tell you.

I see that here with the American Logic of "why don't they make a custom drawing for every vehicle built" which in essence is what you're implying taken to a logical OEM standpoint (The company I work for does this, from their history in API, unfortunately in the  Industrial Market where costs are paramount, they STILL have yet to figure out how to draw a 'universal' wiring diagram that covers what are supposed to be STANDARD BUILDS and use "ONE" wiring diagram for EVERY unit!)

 

They don't do a US Specific Diagram. They did a North American Market Diagram. It's  not just America, there's  Canada and Mexico as well. Why draw a specific diagram per country that covers 400 vehicles, when you can draw one that covers every car on the continent?

 

An interesting aside is that Suzuki DOES do country-specific diagrams. My DB51V has the Japan Market Diagram for only Japan. When it was an Export Model, the entire  world EXCEPT GERMANY had the same wiring diagram for LHD or RHD Applications. GERMANY had (at that time) specific requirements for vehicle lighting. Now, on current generation models of the Every Van, it's Japan, THE WORLD (RHD/LHD as some components 'move around') and EURO-ZONE.... Europe has standardised now and requires, apparently, that manufacturers comply with some standard callouts (as noted above, VW Wiring diagrams have been this way for decades!)

As for assigning Meanings "M=Maximum, D=Drive" why isn't it enough that they are simply "M" and "D"? There may be a logic to what letters they chose, but there may not be. At that time, the Japanese had some very strange translation issues... it was all over the industry. The Fairlady 432R has the Chassis Code "PS30SB" whereas a run of the mill not-intended-for-straight-to-racing-duty 432 got Chassis Code "PS30"---what> "PS30 Special Bersion"---and I'm NOT kidding! So you MIGHT think you are assigning logical names, but usually somewhere somehow the kid withthe camera saying 'thankyouvery much, hairpie hairpie" came back to Nissan in the late 60's and since he spoke such "good" English he dictated the names of things  and someone just wrote down what he said.

 

We had a senior engineer at our Japan Distributor who did our screen translations. It wasn't until he  RETIRED  that they requested that some screen translation Kanas be changed to reflect what they actually meant. Our 'coastdown timer' had been translated to "Gone on Summer Vacation".... the first Field Engineer that got an ENRAGED customer calling wanting to know why his forging plant was down and his machine tripped to "Go on Summer Vacation in October" was NOT easily translated  on our NCR paperwork!.

 

When Training on these electrical circuits instructors  would say "The  M Contact Set to the Headlight for Passing" or whatever. They were called  out by letter or number and rarely anything more. We do similar in our training "Power to Energise CR1A initiating Switchgear comes in on A1 and through the coil, exiting A2 to Earth." That's technically not what it does, but it's  how people conceive it does so that's how it's explained. They could have "Special Bersion" all over that diagram!

[Domzs]

Pin 11 does not mean you are looking at a connector with more than 11 pins to find pin 11 . Look at the whole picture , they are more than one connector . For example , a 6 pin connector is labeled 1-6 and a 4 pin connector is labeled 7-10 , so pin 10 is located in 4 pin connector . Hope that help . That's just how they did it . 

[Domzs]

B = battery ( + ) and P = park lamps , maybe . 

[Bob_D]

Tony, you have probably hit the nail on the head with it being a translation issue. Although, I was looking at the '74 wiring diagram for the headlight circuit, and they actually label the high beam indicator lamp as the "Main Beam W/Lamp" and the high beam switch as the "Turn Signal Dimmer Switch". Which leaves me wondering if the Japanese normally drive with their high beams on all the time, and occasionally "Dimm" them for the oncomming traffic. So I'd say at this point that M=Main (high beam) and D=Dimm (Low Beam). I have looked in the FSM for the pin numbering explanation, but haven't found it. What page is it on?

 

Dom, I think you are probably right... it's total pins all together and not per connector. P seems to energize the dash lights if I'm reading this blurry mess correctly (or is it my eyes are just crappy?). The top B traces to the under-hood inspection lamp, the other B traces to the map lamp, so yeah, perhaps it does corrospond to BATT+.

 

The only question I have left now is my red "H" in the combo switch. I *think* it may actually be a B from looking at the '72 wiring diagram, but it may also be an E. It's really hard to tell because my manual and the down-loadable PDF's are all kinds of blurry in that area of the chart. Does anyone out there have a better copy?

[Tony D]

Pin 11 does not mean you are looking at a connector with more than 11 pins to find pin 11 . Look at the whole picture , they are more than one connector . For example , a 6 pin connector is labeled 1-6 and a 4 pin connector is labeled 7-10 , so pin 10 is located in 4 pin connector . Hope that help . That's just how they did it . 

This is what is explained, with diagrams, in the FSM section... I saw it so long ago I can't tell you where or what FSM...I just remember it's in there!

 

As to the driving issues, the JDM models have a SEPARATE switch that works in conjunction with the combo switch to control parking lamps. There is a small socket for the Parking lamp light in the S30 turn signals, sometimes it;s plugged with a rubber plug, other times the hole is not there at all. THAT was your parking lamp. The lights that come on when you turn on the combo switch are something other than "Parking" lights... that was indeed a separate circuit in the JDM and could be lit independently (turn on only left side or only right side per traffic laws in Japan --and California incidentally-- which require the side of the vehicle facing traffic when on the shoulder have the lights illuminated after dark while parked there.) 

[Bob_D]

OK, I found on pages BE-22 and BE-23 a nice description of the combo and dimmer switches, and it answered my question regarding the red H... it is a B after all. I have updated my diagram, and am attaching here for everyone to use. Blue X = "OFF". You may notice that some connections show two different wire colors, (numbers 1, 2, and 14). This is not based only on the FSM, but rather what is in my car as well. I have several electrical issues with this car, so I figured I'd start my own wiring diagram to document what I have, and then compare that to what is in the FSM. Between the missing stock (and aftermarket) radio, the missing dealer installed AC, and the interesting anti-theft "hidden button that must be pressed" to start the car (that the original owner put in, then my brother bypassed, but left in place), not to mention 40+ years of wear and tear, corrosion, etc. it's little wonder that I'm having some issues. In fact, I'm kind of surprised I'm not having more issues than what I have!

[Bob_D]

Oh yeah, getting back to my original post, does anyone have any other observations regarding the FSM wiring diagram showing things that either don't exist on a North American car (like the fog lights), or that are just plain wrong? I know they did running changes as the year went on (notice the horribly innacurate wiring diagram for the electric fuel pump system!), and they probably produced the FSM before some things were finalized.

[Tony D]

I actually hooked up my electric fuel pump exactly as was described in the wiring diagram...just added the fused pigtail to match the mating connector lagged in the harness below the dash!

[djwarner]

I don't know about the later years, but my Series I car is prewired for fog lights and step lamps. The bullet connectors for these are buried inside the wire bundles. The easiest ones to verify are the ones in the wire bundle near the horns.

 

Though the Series I never came with an electric fuel pump, mine had one added later with kludged up wiring. Had since been disconnected. When I had the dash out for crack repairs, I thoroughly went through all the wiring and I seem to remember some provision for an electric pump. Since I didn't have one to worry about, I didn't pay too much attention. 

[Bob_D]

Tony, that sounds increadibly dangerous to me because if you get in a wreck the pump will keep working until you turn the key off! My '73 has a wiring harness that connects to both the starter solenoid and the voltage regulator, and drives 2 relays. I believe the starter solenoid will pass power to the first relay, and therefore the pump, then the VR signal triggers the second relay to keep the pump running. In the event of a crash the engine (and therefore the alternator) stop, which kills the power to the relay, and kills the pump, preventing gas from continuiing to spew all over the (hopefully not flaming) wreck that used to be your car. For safety sake I urge you to reconsider how you have that wired up... use a relay hooked to the oil pressure sending unit or something. I know there have been write-ups both on this site and on the ClassicZcars forum on how to do this. Please be safe!

[Tony D]

Yes, what you describe -- that's the stock setup. It's detailed in the green supplemental manual for the 240z. I had all that, but tore it out and tossed it in lieu of a more direct wiring like in a modern vehicle.

 

If you don't want the Datsun Complexity, you simply get the inertial switch from any Ford vehicle (I stole mine from a wrecked Ranger's passenger footwell under the floor mat) I bolted it into the floorboard same as in the Ford Ranger I took it from, and merely extended the wire out of the fuse box to hook through it.

 

Running out to a 280Z oil pressure switch seems a pain to kill the pump on an engine stall. Hard impact or rollover is one thing. I never liked the oil pressure switch idea as I've seen crashes so hard the throw the car into neutral, and then deformation pins the throttle around 2,000-4,000 rpms....nothing in the original system will kill the power to the fuel pump in that instance...an inertial switch from a Ford will--I would highly suggest you implement an inertial retrofit into YOUR circuitry as I have SEEN what happens when the engine does not stall! More than once, in fact. Ford's switch is VERY good at what it does, and is easily resettable without having to fire the engine first to reprime dry float bowls after maintenance.

 

If you don't have the supplemental manuals for your vehicle, you are using half the information available.

 

There is ABSOLUTELY no mention of a "2+2" in the 260Z manual...yet one exists. To get wiring and servicing information you need the "Green Supplemental Manual" they came out mid year to update the original FSM with regular production line changes.

 

If this is the first you've heard of these manuals, this may be part of the misunderstanding previously.

Edited July 8, 2014 by Tony D

[Malarkey]

That's a good idea to wire in an inertial switch. Thanks Tony. Next time i'm at the local pick and pull i'm going to get one.

I have noticed some of the same wiring diagram issues. My car has wiring from 72/ 73 an some auto/manual harnesses. So far ive been able to locate answers to any questions by lurking about here.

 

You have it right about the fuel system. You won't find wiring diagrams in the FSM for it. The '1973 240Z 1974 260z Fuel System Service Modification Plus' service mod added the electric fuel pump. The modification also added a couple of relays, and a harness in the engine compartment and a harness under the dash. The harness in the engine compartment adds a wire to the starter solenoid connection, and the yellow(?) wire from the voltage regulator (That's the most kluged one. I threw one in the trash before I knew what it was). The harness under the dash picks up the green wire from the fuel pump circuit and goes to the relays. You can find the mod pages on:

http://www.xenons30.com/reference.html

[Tony D]

The S30 (JDM) wiring diagrams have the electric fuel pump on them as it was used in that market. The body harnesses were similar, as noted above some are "universal" with lagged wires not used on either end of the circuit.

 

The service supplements give details not found in the basic FSM. It just occurred to me that when someone uses "FSM" they may literally mean just the big thick book, which as the OP spoke about "was an initial issue, before things were finalised" which triggered me that he didn't know about the supplements--as that is EXACTLY what the FSM is: "initial issue"... It in no way documents everything that was a production change after publication.

 

Those are the a Green Manuals, as well as that "Fuel System Modification" manual specifically for the troublesome EGR-Equipped Models.

[Tony D]

I refer to Ford Inertia Switches as "yard entry compensation"... If you follow that.

 

I use a Ranger as it was the first time I encountered that floorboard location. I was more adept at snaring Tempo/Topaz units from the trunk, as with a wire cutter and a knife you can harvest close to 3' of wiring harness out of the trunk bundle making installation in other vehicles a snap!

 

I considered something near the Trans tunnel near the drivers side seat where the back package shelf meets, I think that would take a good poke to trip. It would be easy to reset from a hard jar without leaving the seat, which (as you will see below, was a valid concern...haha!) I was told almost anywhere securely bolted to the chassis is good, and it will trigger reliably in an impact.

 

I know when the Tempo/Topaz was in rental fleets it was a good joke to "bumper car" a fellow worker's rental car in the Hertz parking area and leave them stalled/stranded as you ran off to the jobsite! That was a little too sensitive for my tastes... But impressed me on switch functional reliability and repeatability for sure!

Edited July 8, 2014 by Tony D