Ok you may already know that I'm going to be installing a 96' 240SX interior into my car soon.
Here's what it looks like

Well I'm in the process of deciphering the wiring that I'll have to do to get the 240sx dash into the Fiero. I will be using the 240sx air system controler. The hardest parts will be removing the cable operated temp setup and installing the electric one from the 240sx. So I'll have to go get that part. Also I've noticed the 240 has the option for floor and def to be on at the same time when the fiero doesn't so that's an issue. Depends on if I want to make it work or not. But for the most part it doesn't look too dificult. It's going to take a couple relays to help adapt it but not many.

I've located the speedo circuit wires and will be testing them soon. I'll be enlisting the help of my cousin on possibly converting the signal to accept the fiero signal and output the nissan equivelent. I'll try to see if the controller will be able to be adjusted for calibrating and tire differences. Probibly won't be too difficult. on the controller.

I've noticed the 240sx has many indicator lights and I plan to take full advantage of them all. I've noticed it has a low fuel indicator that would be nice to have but if a guage in your face isn't enough, get help! I'll look into finding a way to monitor the fuel pressure and if it falls below an adjustable set point then the light activates. Low washer fluid I'll actually use for what it's for. There's a Brake light and a Parking brake light. I'll see what I can do about splitting these on the Fiero, should be easy. Not sure yet what I can do with the Airbag, ABS and Security lights. Might be able to change the image displayed on them to show something else but I doubt it.

Power mirrors, windows and door locks are going to be a breeze even if I have to use relays to adapt them. On the dash there is a Hazard and a Rear window defroster buttons. Since the fiero has the hazard on the column and My fiero doesn't have rear window defrosters then I may make them function something else.

Wish me luck on this project as I'm not sure just when I'll start but I'll have everything drawn out for it. If any one knows of cheap - Free interior wiring harness for a fiero let me know. I don't need the connectors just the wire. I'd rather not use other colors or codes than that of the fiero since it would only make things more confusing to me and anyone going off my notes.

Thanks for listening,
Stuart Lowery
Cleburne, TX
texasfieros.com

p.s. This thing is going to haunt me in my sleep.

Good luck with this project...
Looks like a really nice dash

For the Fiero's cable heating system, adapt the 240sx controls to opperate at RC car servo or a door lock actuator.....

For a door lock actuator it would require several and stage them. Then it would require adition of limit switches in the air mix valve and switches in the controller to be added. That's Too much work.

For an R/C car servo it would require take either converting the variable resistor values to Pulses per minute then sending that to the servo using a 5volt signal and power source. Not to mention a servo.

Instead I'm going to go back to the car and get the 240sx air mixer valve. That would make it much easier. If I couldn't install the valve on the Fiero box I can adapt the motor to control the Cable instead.

Look's very nice and I think it fit's the Fiero very well!!

Are you going to make this thread, your 'build-up' thread..?? I wish I would have done a build thread for mine, but just imagine a 2 year thread..

Good Luck with the project!!

Steve

------------------
New Name.... New Attitude....
AKA. SmoothGT....

Custom Made WIDEBODY 1986 GT!!

I'm going to make several build up threads. One Highly Technical per task and one main one to summerize it all. Should take about 2 years to complete due to fundings.

Good luck Stuart. I'll be sharp looking.

Bob

Thanks for the support guys. Last time I posted anything about this setup I got a "At least stick with the same brand. AKA Pontiac Firebird dash....You gonna' hook up some glowing nissan badges on the back of your fiero too?" Reply. Also ferrari_momo is interested as well. I guess he has a 240sx as well.

So any way Tonight I'll be hooking up the speedo to my old computer and testing to signal required to display certain speeds. Wish me luck since my results will decide on what I'll have to use to convert the signal over.

I've heard I could use this converter from Dakota Digital to do everything I could possibly need but being tight on money I'd rather spend less. So since my cousin knows about programming chips maybe we can get one together and make it have calibration features as well.

I'll be returning to the salvage yard this weekend to get the rest of the HVAC system from the car just in case. Heck I may grab all of it and see what all I need since it's possible that if I used it I could have SPLIT Floor/Defrost option which our Fieros don't have.

Wish me luck.

Have you considered taking the whole Nissan wiring harness, finding the 'outward' most points (electrically - where things become there most basic), then splicing those into the fiero harness?

It'd save a LOT of fiddly hooking up.

I don't know about Nissan's mantra when it comes to harness's, but GM tends to do things in a somewhat modular fashion. Like, you can take out JUST the cruise section, or JUST the power window section of the harness. Of course, you couldn't easily take out JUST the front injector bank wiring... but you know what I mean...

Anyhow, look at both the diagrams, find both of the 'outward' points, then mate one to the other there (with appropriate signal converters like for the VSS).

------------------
87/88 V6 5spd "FormulaGT"

My pages: http://www.fieroclub.com

http://www.fierohut.com

I know what you're saying but when it came down to it all I could do was hack off the wires as far into the harness as I could. The interior harness is really tangled into the reinforcements of the 240SX. I wanted to try to get the whole thing but it would have taken FOR EVER to get it out unharmed Plus I wanted to try to do this without having to remove the fiero harness from the car just remove the plugs and splice in from there. I'm going to try my hardest to DOCUMENT EVERY WIRE for reference reasons and maybe to share a wiring diagram as well. Heck, after my cousin and I design the Cluster interface I may build a couple extra to sell with the HOW-TO instructions. From looking at both of the wiring diagrams Nissan vs. Pontiac there's a lot of wires that do the same thing but theres a TON of other stuff to and different SIGNALS as well. Believe me when I say this is going to be one heck of a challenge and I plan to hopefully to have the Most functional swap completed when I'm done.

What signal does the 240 speedo need? You can get a VSS buffer box from any 3rd gen F-body that will convert the Fiero 2000ppm AC wave to a buffered 2000 or 4000ppm square wave. The box is smaller than a pack of cigarettes and is available at any junkyard - mine was free.

Schematics are somewhere on the web. If this will work for you, I will try to find the wiring diagram I used when I hooked up my Grand Am gauges. I needed buffered 4000ppm, and was looking at the Dakota Digital unit ($300).

Does the Fieros really have 2000ppm? I thaught it had 4000ppm.

If I'm wrong please tell me. Cause all I need is 2000 ppm Square to run the speedo that I have.

Sorry, I had it backwards. It is 4000 from the VSS, but it is a sine wave, not square. The buffer box I have produces both a 4000 and a 2000ppm buffered output from the 4000ppm input. I think it was split so the speedo got one input, and the cruise control got the other. I needed 4000ppm for my speedo, but the AC sine wave wouldn't drive it.

The speedo board in your Fiero cluster already produces a 2000ppm square wave and sends it to the ECM. Look for an 8-pin chip with the number 6758. Pin 8 is 2000ppm, Pin 7 is 4000ppm. Follow those 2 pins back to the edge connector on the board. If you have a Fiero schematic, the wire from the speedo to the ECM is what you are looking for - 2000ppm buffered. I just used the F-body box because I didn't want to stuff the whole board behind the dash and insulate it.

Where is this box located in the F-body and what does it look like?

It's a square yellow box about 3" x 2" x 1/2" thick. It rides piggy-back on the ECM, which can be found in the glovebox area under the dash. Be sure to cut off the pigtail if you find one - you'll need the connector.

I just found the link to the info I used:
http://chevythunder.com/fuel%20injection%20elect.%20pg%20B.htm
Scroll to the bottom of the page.

Shows you the box and the wiring.
Good luck with it.

[This message has been edited by Gary W (edited 01-01-2004).]

Here's some of my progress. Being concerned with the speedometer I wanted to make sure of a couple things. #1 does it work (YES IT DOES) #2 What is the actual Pulse Per Mile (NOT SURE YET)

Here's my findings. To Display 90MPH It required 200hz I cannot get it to reach 100 MPH and I believe it's due to lack of voltage. The voltage that my sound card on my test computer is around 700mV Which I think I need to be close to 1 Volt to reach over 100MPH.

Also with my calculations, which must be wrong, I found 50Hz to be 90MPH for the Nissan cluster. Boy was I way off. I also found that square wave and Sine wave didn't matter to it. It read both as being the same, yet Sine wave didn't put out as much voltage for it.

The sine wave will drive it, but if it's anything like mine, it won't work well below about 15 MPH. I think it's an amplitude problem.

Your best bet would probably be to hook your DVM inline with the Fiero VSS, check ouput readings at a certain road speed, then pull the VSS and drive it with a drill to duplicate the output and see what your Nissan speedo says at the same output.

The fiero VSS is 4000 pulses per mile if that info is of any use to you.

------------------
Dave E

www.ltlfrari.com

GARYW
What all cars do you know that Buffer sits in? I looked in several cars mainly F-bodies between 86 - 92 and didn't find a single one. I did see this larger black box and got it but I now see that it isn't the same thing.

[This message has been edited by stuartlowery (edited 01-04-2004).]

So you're using a sine wave output from your soundcard to generate a signal simulating the VSS? I don't know if that will work. I think the output of the Fiero VSS is well over a volt.

You're working too hard. Hook it up to a low-voltage DC transformer. It should read 54MPH. 60HZ right out of the wall. That's how I tested mine.

I'll be upgrading the sound card in the Test computer to one that's capable of a 2 volt output at full blast ( I hope). I want to set up a test bed having both the Fiero cluster and the 240sx cluster side by side to watch them for differences in readings at other given frequencies. I under stand you think this is overkill but right now I can easily test the 240sx cluster up to 95MPH just don't have the voltage to go higher at this time. I will soon see if I can help that out using a better sound card or possibly amplified speakers.

Why is it when I apply 60hz to the Nissan cluster I get 27MPH? Here's my reason behind the question. If the Fiero uses 4000 Pulses per mile and the Nissan uses 2000 Pulses per mile then should the nissan show 114 MPH at 60hz?
Something doesn't seem right about these tests.

We make some speed switches here at work for use on UPS vehicles. Some require square wave inputs, while others require sine wave inputs, depending on the vehicle. You may be having a problem with the cluster circuit interpreting the sine wave. That and a sine wave goes negative, which might not be good for the circuit unless it is protected.

If you are looking for accurate results, you should be using a square wave generator...you can use a modified version of Rockcrawls passkey circuit: www.fieroaddiction.com which has work fine for me (or a signal generator)

Tim

Ok using a small transformer to drop down 60hz to about 4.4 volts then using resistors to drop it down to 2.2 volts I tested the cluster with that. AT 60HZ the cluster registered 27 - 28 MPH. Why in the world would it do that? I guess I'm going to have to ask again what Pulse/Mile that sender sends out. This is beginning to be a major pain in my rear. I would be correct in assuming that a Fiero cluster displays 54MPH at 60hz. Right?

[This message has been edited by stuartlowery (edited 01-05-2004).]

quote Originally posted by stuartlowery: I would be correct in assuming that a Fiero cluster displays 54MPH at 60hz. Right?

Wrong. The Fiero Cluster is 60 MPH at 60 Hz. That is one of the nice things about the Fiero. One MPH equals one Hz.

BTW, have you checked Oliver Scholz webpage? He has done bazillions of Speedo mods. One may help you out.

http://www.fieros.de/en/main.html

[This message has been edited by Toddster (edited 01-05-2004).]

Toddster sorry to correct you but GM uses a 4000 Pulse ? Miles signal which would come out to 54MPH. I just wanted someone to say I was correct so I wouldn't think I was crazy. But this confirms my thaughts...
The speedometer should read:
60min x 60sec x 60 cycles / 4000 pulses per mile = 54 mph.

And here's my thaughts on the Nissan speedo... This is a C&P from the nissan forum of a post I just made.

Please correct me If I'm wrong but I'm feeding a signal of 60HZ into the nissan speedo I should recieved 108MPH if the speedo runs directly from a 2,000 Pulse/ Mile Signal. I'm not getting that instead I'm getting 27MPH which would mean the speedo is tracking off of a 8,000 Pulse/ Mile signal.

Here's the math

((Hz*60)*60)/MPH=Pulse per minute.

60hz = cycles per second

So if I take 60hz and convert that to minutes that would be

60*60=3600 And convert that to hours would be

3600*60=216000 Now let's take the displayed MPH and devide that by our cycles per hour to get cycles (pulses) per Mile. So that will be...

216000/27MPH = 8000 Pulses / Mile

Any math majors able to confirm that?

I second the motion on adopting a square wave generator. If you are using AC voltage albeit reduced, I would expect you to recieve a signal that is still sinal in nature. Wall current is supposed to be 115V 60Hz. One cycle starts at zero volts, goes up to 162.5 volts, down through zero to negative 162.5 volts and up to zero. The 115 volts you end up with is root-mean-square voltage, which is to say that the voltage given as 115 represents the average potential difference "under the curve" so to speak, disregarding the negative nature of the other half of the cycle.

If the Nissan gauges are just simple type doodads and only look at the frequency with which the signal changes from (potential) to (no potential), they will be seeing twice as many pulses as you think you are sending them, due to the fact that the AC wall current's cycle passes through zero as the voltage goes from "push to pull"

Therefore, I would hypothesize the Nissan speedo to be a 4000 Pulse Per Mile type doodad.

Good Luck
Kurt Kimmerly

*Doodad-a fun technical term which may be used appropriately in many contexts

quote Originally posted by stuartlowery: Toddster sorry to correct you but GM uses a 4000 Pulse ? Miles signal which would come out to 54MPH. I just wanted someone to say I was correct so I wouldn't think I was crazy. But this confirms my thaughts... The speedometer should read: 60min x 60sec x 60 cycles / 4000 pulses per mile = 54 mph.

You're right. My mistake. My math skill drop off after 8:00pm.

With that in consideration I need to disclose the TESTING STEPS for the nissan sending unit. I was told it was just a switch that toggled a 12Volt pulse from a Nissan forum. Well That sounds good until you turn the page and see how to test the sender. It says to hook a DVOM to it and read A/C Voltage. Then to spin the gear on the sender quickly. The reading should display around .5Volts or more if it's good and nothing if it's bad. Well if it's HAND spinning that causes the voltage then it must creat a Sine wave. A square wave would be that of a switch or trigger wouldn't it? Any way I believe I have found what I ned to use and will begin getting the parts for the circuit ASAP. I'll keep you posted of my progress. Hopefully I can get this dash istalled soon but with all this COLD AIR OUTSIDE I may not be able to without a heated Garage or something to get out of the weather.

Just an idea I can pass on to you during those undescribable frustrating moments of ohm, VSS, voltage testing, over-amping testing proceedures. I suggest dipping into that White Lighting sitting underneath the TV in the milk jugs. A good strong "swaller" (maybe two) can clear the cobwebs so as to make your next connections that much easier to do. I like your resolve to take on such a challenge. Great imagination.

Sincerely,

Kevin J. Sullivan

quote It says to hook a DVOM to it and read A/C Voltage. Then to spin the gear on the sender quickly. The reading should display around .5Volts or more if it's good and nothing if it's bad. Well if it's HAND spinning that causes the voltage then it must creat a Sine wave. A square wave would be that of a switch or trigger wouldn't it?

Not neccessarily. If it is a hall-effect device, or reed-switch device, creating the pulses, it could go zero to 12V in a square wave fashion. You would have to have the meter on AC to measure anything because the pulses are too quick/short to measure at DC.

RCR but if it used reed switches it wouldn't create voltage. And there's only two connections on the Nissan VSS and No source of power. So there is no way to generate power for this test if it was a switch. So It must be generating power. Thus AC SINE WAVE.

Kevin I appreciate what you say but honestly I didn't think of using the Nissan Interior. I was more like PUSHED on me by a freind that knows of one other Nissan Interiored Fiero. The only reason I can't just copy what that one did is cause he used the Fiero Guages behind the Nisan guage faces and Fiero switches and A/C Controls too. They are not accurate but they do work. After you all get to know me even more you're 1 going to get annoyed of me and 2 going to figure out I'm very picky about EVERYTHING working. I also don't jump into anything without knowing that I have tested it and it works. So none of this will be installed until it COMPLETELY WORKS. This includes NISSAN A/C Controls, Window Switches w/ Auto Down, Door Locks, And everything else. With that in thaught I remember that the Nissan uses a Column Mounted Head light switch So I'll have to incorporate one in from a different car and make it look like it belongs there (that'll be fun.) Also I'll have to add in a Trunk/ Deck Latch button as well. I'll add more later when I get back from Work.

[This message has been edited by stuartlowery (edited 01-06-2004).]

quote Originally posted by stuartlowery: RCR but if it used reed switches it wouldn't create voltage. And there's only two connections on the Nissan VSS and No source of power. So there is no way to generate power for this test if it was a switch. So It must be generating power. Thus AC SINE WAVE.

The Fiero VSS is a reluctor. Basically a small AC generator. It creates an AC sine wave of increasing frequency and voltage as RPM increases. It is bi-directional. From the service description, it sounds like the Nissan is too. No way to create voltage without a coil and a magnet. I still think your best bet would be some empirical testing with a Nissan VSS and a fixed RPM motor.

quote Originally posted by stuartlowery: With that in thaught I remember that the Nissan uses a Column Mounted Head light switch So I'll have to incorporate one in from a different car and make it look like it belongs there (that'll be fun.) Also I'll have to add in a Trunk/ Deck Latch button as well. I'll add more later when I get back from Work.

I got a Grand Am column in with just a few structural mods. Getting the electronics -especially the delay wiper circuit - to work was something else. Stalk mounted headlight switch, hi-beams, pulse wipers, even the cruise works. Used the GA ignition switch, too. Take a look at one of these ('92 - '95) and see if it fits the style of your interior. If so, I can share some tips on getting that stuff to work.

[This message has been edited by Gary W (edited 01-06-2004).]

quote RCR but if it used reed switches it wouldn't create voltage. And there's only two connections on the Nissan VSS and No source of power. So there is no way to generate power for this test if it was a switch. So It must be generating power. Thus AC SINE WAVE.

Good call Stuart. I guess I gave too much advise without enough info. Sounds like you know what you're doing, just need some clarification on why things work. You'll get it.

PS good luck. Sounds like a cool swap.

Bob

quote Originally posted by Gary W: I got a Grand Am column in with just a few structural mods. Getting the electronics -especially the delay wiper circuit - to work was something else. Stalk mounted headlight switch, hi-beams, pulse wipers, even the cruise works. Used the GA ignition switch, too. Take a look at one of these ('92 - '95) and see if it fits the style of your interior. If so, I can share some tips on getting that stuff to work.

Sounds great I'll take a look at one. I'll be Salvage yarding again this weekend although will be on a tight budget. Can you tell me what you gave for yours so I'll have a ball park figure to go by?

This thing is going to be mighty scary to draw the schematics for andI wonder what I'll call it.

The Pontiac Nissan Fiero Grand Am Prix GTP 240SX? WOW that's a lot.

[This message has been edited by stuartlowery (edited 01-07-2004).]

quote Originally posted by stuartlowery: After scowering the net looking for good detail pics of the GA Column I say I have to go that route. That has exactly what I need. Thanks for the heads up. This is the colomn you are speaking of right? Best pic I could find

That's the one, but that looks like an airbag car. You might want to stay away from that one, because you have an extra slip ring on the column for the airbag, plus it's rigged for DRL's. The DRL light switch will not take the full current of the Fiero lighting system. I have the smoke to prove it. You can also look at the other N-bodies - Olds Acheiva, Buick Skylark, '92-'95. The GA has a square profile, the others are somewhat rounder. The basic electronics are the same, but I found out the hard way that the stalks are not interchangeable between the different brands. Auto and stick columns are different. I used an auto column in my 4-speed and hacked the park interlock. I paid $25 each for tilt columns at the u-pull. I also got an armload of extra control levers for $10.00. You will need 2 of the wiper controls in order to cannibalize the boards, unless you have easy access to many values of SMD resistors. I found that the resistors on those boards, doubled up in parallel, made an excellent replacement for the Fiero potentiometer (GA has a 5-position pulse wiper, not infinite like the Fiero).

You will also need a donor Fiero column for the mounting brackets. Minor welding required. If you go this route, I HIGHLY recommend getting a factory schematic for the Grand Am. I had a Chilton's manual, and it was all wrong. Spent half my time just figuring out which wire did what.

As far as SMD Resistors I can get any I want since I'm not far from Mouser Electronics. I can build any controller that I may need to get past smoking a column. I want to find the best fit and work from there.

[edit] Wow one more post and this'll hit 2 pages. That'll be a first for any of my posts [/edit]

[This message has been edited by stuartlowery (edited 01-07-2004).]