quote Originally posted by L67: You should go back and make solders, especially at the C500, which is exposed to the elements from the right engine vent. There's 23 solders to make, just knock them out so that you won't have to track down electrical gremlins later. I've seen what someone else's swap harness with crimps looked like after a few years of use, I felt bad for the guy.

I might go ahead and do solder at the 500 since it is outside the car. On the inside , it is just easier and quicker to crimp them. After I get it running, its all coming back out anyway and im sure I will be cutting the harness down shorter and I will solder all connections then.

Steve

quote Originally posted by JumpStart: I think I have finished wiring up the 203 but did not see in any pinouts a place to wire up pins A,E,G,H,P,R Are these unused pins on the 203? Thanks, Steve

A is not used

E goes to the center pin of your oil sender

G If you are using an auto trans goes to the speedo buffer output (you build speedo buffer circuit) If Manual trans it goes to yellow wire from the VSS and is split to go to the PCM VSS high input C1-64.

H Not used

P to the PCM C1-30

R Not used

I drew this up for the speedometer circuit. Thought it might help you, so what the hell:

[This message has been edited by L67 (edited 01-25-2011).]

quote Originally posted by Mike Gonzalez: A is not used E goes to the center pin of your oil sender G If you are using an auto trans goes to the speedo buffer output (you build speedo buffer circuit) If Manual trans it goes to yellow wire from the VSS and is split to go to the PCM VSS high input C1-64. H Not used P to the PCM C1-30 R Not used

I am confused. Why would this circuit be different auto vs manual trans?

quote Originally posted by phonedawgz: I am confused. Why would this circuit be different auto vs manual trans?

Because the Fiero Manual VSS will run the speedo, so can run direct, the PCM just also needs connected to know if your moving or not.

With the auto trans, 4T65E, the PCM needs the signal for shifting, lockup, general drivabilty. The PCM output signal is wrong though and needs modified by this buffer circuit for the speedo to recognise it.

That makes sense. So a manual tranny setup COULD wire the VSS to the ECM and use the buffer circuit but no need to.

Yep

Thanks

quote Originally posted by Mike Gonzalez: Because the Fiero Manual VSS will run the speedo, so can run direct, the PCM just also needs connected to know if your moving or not.

The computer we're talking about needs a 24,000 ppm anolog AC signal. The older Fiero transmissions output a 4000ppm digital signal. Even if you connected the older VSS, the computer still won't know how fast the car is moving.

quote Originally posted by L67: The computer we're talking about needs a 24,000 ppm anolog AC signal. The older Fiero transmissions output a 4000ppm digital signal. Even if you connected the older VSS, the computer still won't know how fast the car is moving.

Uhh, it works just fine. The fiero VSS just is a bit slower than the 4t65e, but you can change that in the PCM. The VSS is required for correct function of the idle follower functions in manual swaps.

quote Originally posted by: Darth Fiero @ Motorswap.org Here is where it gets tricky. Most 3800 pcm's like to see a 29-31 pulses per tire revolution signal from the VSS (depending on reluctor count). Using the standard tire size from a 3800 SC equipped vehicle, this works out to about 24,000 pulses per mile; which is about 6 times the amount that the stock reluctor from a getrag gives out. Another problem is the 3800 PCM is looking for an analog VSS signal whereas the stock getrag is a digital signal which most PCM's are not compatible with on that particular input. I have not ever attempted to make the stock PCM programming compatible with the getrag signal but it may work. It also may need an adapter to work, one similar to the diagram I have on my website at http://dtcc.cz28.com/fiero/fmods.htm . While you don't really need an accurate signal if you have a manual trans, the PCM would like to see that the car is moving or it is stopped for drivability and idle issues. If you are using a non-electronic auto and still want the PCM to control the TCC normally, you will need to get this signal pretty close otherwise the PCM will assume you have a slipping TCC issue or incorrect vehicle speed and will disable TCC operation.

But aren't all Fiero VSS's geared to output exactly the same? There is no difference between a manual and an auto speedo. So you are saying the wiring stated before will work for a 4t60 but not the TH125C or any of the manual trannys or?

And what about analog vs digital? Is the TH125C VSS digital or analog? All MT VSS's are the same so they are all digital?

quote Originally posted by phonedawgz: But aren't all Fiero VSS's geared to output exactly the same? There is no difference between a manual and an auto speedo. So you are saying the wiring stated before will work for a 4t60 but not the TH125C or any of the manual trannys or? And what about analog vs digital? Is the TH125C VSS digital or analog? All MT VSS's are the same so they are all digital?

Yes, all Fiero transmission use the older 4000ppm digital output, including the TH125c. I have no idea which type the 4t60 uses, but the 4t65 uses the 12,000ppm anolog output. Luckily the Getrag F23 also uses this new signal standard. The 3800 OBDII computer is looking for this input. The older generation transmissions don't use it, and I have no idea how the computer interprets the six times slower digital input from the older sensor.

[This message has been edited by L67 (edited 01-26-2011).]

quote Originally posted by L67: I drew this up for the speedometer circuit. Thought it might help you, so what the hell:

I guess the guys at Radio Shack will know what I need . I have never messed with circuitry before.

[This message has been edited by JumpStart (edited 01-26-2011).]

That should make it interesting

Resistors 1/4 or 1/2 watt are fine. $0.99 for a pack of 5 at RS
Diode - This device is polarity sensitive. The end with the silver paint matches up with the side with the | (not the side with the triangle)
Capacitor - make it at least a 20v cap. There will be a negative lead on the capacitor. That aligns with the straight bar in the diagram.

Ok , back to the 500....

Sometimes looking at 3 different pinout gets confusing lol.

On the 500, I am planning on using C1 and E1 plugged in to the tranny for my backup lights, E2 goes to the starter.

The other wires..
B3 Charging System
C2 Indicators
C3 Tach
D1 cooling fan
D2 cooling fan
D3 instrument Panel

Im still not sure about. I assume that they all plugged into the part of the harness that is still with the car.
C2 and D3 have clips on the end and are joined together as if they both go to the same 2 prong plug that plugs into a set of wires that go to the insturment pod. I have no idea where this plug is or was.

Any ideas? Thanks again

Steve

B3 Battery light, goes to C1-36
C2 Temp sender, goes to pin 3 Green of the coolant temp. sender
C3 Tach feed, goes to pin E white of the ICM
D1 Fan relay control, goes to C1-6
D2 Not used
D3 Hot temp lamp, goes to C1-75

I had to type this twice ! I replied once and it got lost !

Anyway, all these connections are on that spreadsheet.

quote Originally posted by JumpStart: Ok , back to the 500.... Sometimes looking at 3 different pinout gets confusing lol. On the 500, I am planning on using C1 and E1 plugged in to the tranny for my backup lights, E2 goes to the starter. The other wires.. B3 Charging System C2 Indicators C3 Tach D1 cooling fan D2 cooling fan D3 instrument Panel Im still not sure about. I assume that they all plugged into the part of the harness that is still with the car. C2 and D3 have clips on the end and are joined together as if they both go to the same 2 prong plug that plugs into a set of wires that go to the insturment pod. I have no idea where this plug is or was. Any ideas? Thanks again Steve

I have these posts seperate to help you keep them seperate

D2 won't be used with the 3800. You only need a high speed fan. The two speed fan was only on '84's

D1 should go to the ECM output for fan control.

Are you feeding the pink wire to the Ignition 'brick' with a wire from C203? Normally it would be fed by E3

You have a wire on A2 to engine ground?

Ok...This is making more sense now. It might be a few days before I can get back to it but now I know I need to trace a few wires down.

Thanks phonedawgz and Mike

Steve

[This message has been edited by JumpStart (edited 01-27-2011).]

Your welcome

I picked the car up off the drivetrain yesterday to get a better look at the wiring and found that part of my harness was pulled down behind the engine when I lowered the body. This was part of the reason I was confused not being able to find the connections. Well now I have them and they were already labled.

One of the wires from the 500 seems to have broken off and I cant see how to remove the plug,prong whatever it may be called, so I can get a new wire on it and plug it back into the 500.

Any ideas? Should be working on it this afternoon and some tomorrow. Thanks

Steve

[This message has been edited by JumpStart (edited 01-30-2011).]

This is on the body side of C500?

The part I am talking about is the one that goes with the harness, not the part that is bolted to the car itself. The wire broke off the plug leaving a few pieces of wire barely sticking out. These pieces of wire are crimped into the back of the prong (whick sticks out on the other side with the others) and plugs into the part of the C500 that remains with the car.

I think it was the D3 wire that broke.
Ill take and post pic if needed
Steve

Here is your answer. If you have wires no longer used on C500 you can use the pin from that position. Or perhaps you can pull the pin from the connector and replace the wire with it off.

Here is how

https://www.fiero.nl/forum/Forum2/HTML/099987.html

Got it out and a new wire on. Thanks again for the info and The Ogre in the link. Gettin a little closer everyday lol

Steve

quote Originally posted by Mike Gonzalez: G If you are using an auto trans goes to the speedo buffer output (you build speedo buffer circuit) If Manual trans it goes to yellow wire from the VSS and is split to go to the PCM VSS high input C1-64.

I am using a 94ish Beretta 5 spd. Will I still need this buffer circuit? If so just wondering if it is wired the same as in the diagram because this is not a Fiero tranny.

Steve

No - You won't need it. The PCM only needs an input that shows movement when the car is moving and stops when the car is stopped. Then the only issue will be the speedometer.

ok, saves me a trip to radio shack. On Ryans pinout, C1 Pin 55 is labled 4,000 ppm vehicle speed signal output. Doesnt really say what it is connected to and pin G (VSS High) on the 203 is the last wire on the 203 I need to find a home for (promise lol)

Thanks for the help

Steve

Edit: you just got a well deserved plus PD

[This message has been edited by JumpStart (edited 01-31-2011).]

If your Getrag uses a 4000ppm VSS you will wire it direct to c203 with it split to feed the PCM VSS inputs. The 4000ppm output will not be used unless you need it for digital cruise control/

I looked into it, its a 282 so I think it uses the 20000ppm. I read that it is better to have the ECM programed for the 4000ppm it is looking for. If I go this route, I need to know what to wire up because there seem to be a few way to do this including tricking the ECM into thinking that it is an automatic which is not the way I want it wired.

Steve

With a manual transmission it doesn't matter what the ECM thing the speed is correct? Just moving or stopped right?

Mike?

And if the VSS in the tranny isn't the same as the Fiero VSS couldn't you install the Fiero VSS in the tranny?

Yes, the PCM just needs to know if your moving or not with the manual trans. But since that VSS wont run the Fiero speedo by itself you may be able to run it through the PCM and have speed correction programmed into the PCM to allow the 4000 ppm output to be used to run the speedo through the buffer. I dont think the Fiero VSS could be used on that trans, I think it uses a magnetic sensor rather then a gear to count rev's. You may contact Rodney, he probably knows what that trans's VSS output is, and maybe contact Ryan at Sinister to see what can be done on the programming side of it.

These might clear it up...

The following method will work for all applications and allows the PCM to control speedometer calibration:



The following method will only work if your transmission is using a stock Fiero type speed sensor. This method will not allow the PCM to alter speedometer calibration; and cannot be used with the 4T60-E, 4T65-E, F23, F40, or any other transmission that does not use a stock Fiero type 4000 ppm speed sensor:



Note the addition of the electronic cruise control modules to these diagrams.

-ryan

------------------
OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

[This message has been edited by Darth Fiero (edited 01-31-2011).]

quote Originally posted by phonedawgz: And if the VSS in the tranny isn't the same as the Fiero VSS couldn't you install the Fiero VSS in the tranny?

No, the older VSS's including the one used in Fiero transmissions is driven by a gear. The newer transmissions have a reluctor wheel, which is measured by a hall sensor at the end of the VSS assembly. If you dropped a gear driven VSS into the opening, it would never engage.

Thanks for clarifying that Ryan !! I figured thats how it would work, but wasnt sure !

quote Originally posted by Darth Fiero: These might clear it up... -ryan

Excellent! The first diagram you added the cruise control output, I should have thought of adding that. In fact, I'll go back and do so. May I make a point about the second diagram though? I think it's important to point out that that diagram will work perfectly, if the VSS is the older gear driven 4000ppm digital unit. This older unit is represented as a gear driven unit in the older diagrams. I just don't want anyone reading a diagram and getting confused because they see the newer hall sensor being compatible with Fiero gauges.

For the layman (not Ryan):

Here's a revision:


The older 4000 gear driven can also be represented by this in the older diagrams (as taken from the powertrain electrical schematics of a 1991 Chevy Beretta 3.1L).


The following is the new graphical representation of the 24,000ppm analog VSS, which is hall effect rather than gear driven. Whenever you see this, it's safe to presume the VSS output will be the newer 24,000ppm standard, and will not be compatible with the Fiero gauges.


I hope that makes sense.

Thanks for the help Ryan and everyone else also.

Steve

Revised a bit further... :-)



-ryan

Now we're "cooking with gas".