So, how can we keep this from the trash can? It's a legit posting, with good information.. Let's not let it get ruined with bickering.

1. It serves to show those of us with more money then time where we can get a quality harness..
2. it shows those of us with more time then money how to make our own- if we choose to use Dan's routing.
3. it also shows other options- including cutting an OEM harness.

Can we agree to disagree? There are many ways to go about things..This is just one. If anyone disagrees, by all means create another post, with your pics, and explain how you do things.. This gives everyone options- but keeps each thread tightly composed, and viewable.

Personally I have a car with the "Pre-Skitime" wiring.. I have had quite a few problems so far-wires pulling apart, wires getting cut while driving etc. In my case, I work a lot, and have zero freetime to build my own harness. I would happily pay for a nice, clean, reliable harness- it just makes more sense for my situation.

Dan , and others following this thread, I am watching closely as I plan on doing this to a 4.9 sometime in the next 6 months. Every time you post, I and others, learn something new. Please don't get discouraged and stop your good efforts because of some child like behavior. I thank you for your good efforts.
Joe Crawford, Texas

If you give me the year of the 4.9 you are using I can see about getting you the wiring diagrams for it. Dan

Thanks, but I'M not that close yet. I have 9 grandchildren who's Christmas will come first. I can play again right after New Years Day ! But beleive me I am learning things at a fast rate.
Joe

[This message has been edited by josef644 (edited 11-30-2007).]

quote Originally posted by smartaxel: So, how can we keep this from the trash can? It's a legit posting, with good information.. Let's not let it get ruined with bickering. 1. It serves to show those of us with more money then time where we can get a quality harness.. 2. it shows those of us with more time then money how to make our own- if we choose to use Dan's routing. 3. it also shows other options- including cutting an OEM harness. Can we agree to disagree? There are many ways to go about things..This is just one. If anyone disagrees, by all means create another post, with your pics, and explain how you do things.. This gives everyone options- but keeps each thread tightly composed, and viewable. Personally I have a car with the "Pre-Skitime" wiring.. I have had quite a few problems so far-wires pulling apart, wires getting cut while driving etc. In my case, I work a lot, and have zero freetime to build my own harness. I would happily pay for a nice, clean, reliable harness- it just makes more sense for my situation.

Great response. I am in the same boat where I do not have the time to make a harness... heck, it took me over three months to complete an intercooler install, and that should be a one weekend/one day project. I will gladly pay what Dan asks for a harness, and I am very comfortable around wiring. The thing I really appreciate about this thread is the step by step picture instuctions. If I were to ever take on another conversion, I will absolutely buy a harness from him.

O.K. maybe I missed it. I understand the c500 connector is a junction block that is part of the Fiero, but the c203 connector is that part of the original Fiero wiring too or something that is gonna come off the 3800 wiring harness? Also I noticed that you are labeling the pins A, B, C, etc per connector and stating there old and new location. Are the labeled on the connectors already or something or does everyone else have the GM wiring diagrams in front of them except me? Yeah, I know, dumb questions but I wanna have a nice solid understanding of what I doing before I start.

The C500 is a junction block where wires are fed to the engine and tail lights from the rest of the car. The C203 is a connector inside the console by the computer. It is where some of the wiring from the engine feeds to the rest of the car just like the C500. The letters and numbers are on the connectors if you clean the dirt and crap off them. The C203 has two halves to the connector one has A through H and the other J through R. The C500 has the letters going across one way and the numbers down that is how you get pins like A2 of E3.
So when you make your harness remove the appropriate connector and cut it away from the Fiero engine harness leaving enough wire to work with basically the more wire the better. When your harness is finished you just install it on the engine and plug the two connectors back in.
Because the 3800SC engine harness has the PCM connector on it so all that is needed is to feed the harness with the proper powers and grounds then from the harness feed the proper gauges and the harness is complete.
The main connectors from the 3800SC harness that fed the rest of that car are removed from the harness and rerouted to reach the appropriate connector on the Fiero harness.
For example the C203 connector pin C which is brown with a white stripe is the input to the gauges to work the check engine light that comes from the Fiero ECM. On the 3800SC swap harness you take the wire from the PCM for the check engine light or SES or MIL which ever the diagram calls it and reroute it to the C203 pin C and solder it to the wire you cut from that pin. Dan

Dan, by chance did you have the oportunity to get the speedo ckt info?

Tks

Thanks for the help. So pretty much if I'm gonna be deleting stuff like boost bypass sylenoid, and egr then just dont include those connections in my harness, pop on block-off plates, and get Lloyde to program my pcm?

"C203 pin G this is the speed sensor high feed to the speedometer. This must be connected to the PCM C1 pin 55 through a buffer circuit on auto swaps"

and on manuals?

The fuel pump wiring for the 97 to 2000 models uses two relays one is the fuel pump relay and the other the fuel pump speed control relay. Basically the fuel pump relay switches the +12 volts coming from C203 pin B to the fuel pump through C203 pin L.
The speed control relay switches in and out the fuel pump dropping resistor so the +12 volts either goes through the resistor or bypasses the resistor giving the pump full power.
If you do not want to use the resistor just do not wire it in, what I do then is run the wiring as if the resistor is used then short the wires together that would have fed the resistor giving the pump full power all the time.
the only draw back is the pump is a little noisier during light driving where the SC is not producing boost. Dan

Ok thanks, I understand now. It IS like I imagined, but it didn't make sense that it would go to an outside relay just to come back to the C203 again..

just off hand, do you have any of those resistors?

I have a bunch of them... but you most likely dont want to mess with it..

You need to put a whole load of relays in to get the resistor working correctly, its sorta a pain.

The resistors are known to fail leaving you stranded unless you short out the connector to bypass the resistor but if you want to use one I have a few spares hanging over my work bench from GTP's and Regal GS's I have stripped. Dan

I wont use one

You mean the dark green with white wire for the fuel pump relay yes that is the +12 volts to turn on the fuel pump relay. Dan

On an 1997 GTP OBD II PCM would the first configuration i have drawn be the correct one that you are talking about above?
I had originally thought that i only needed to run the wiring as drawn in the bottom configuration (in which case I would simply unplug the wire to pin 27 on PCM connector C1)
Both configurations run to socket A on the fuel pump relay.



Dan

The second one where the fuel pump relay is controlled by the one dk grn/white wire from the PCM. The second wire from the PCM for the speed cntrol controls another relay if you decide to use it.
Basically if you are not using the dropping resistor the fuel pump is wired the same as the non super charged pumps. Dan

here's a bit of an odd question here. what about using a scan tool for diagnosis/monitoring... would you still use the ALDL connector? or would you have to add in an OBD II connector somewhere. I see that you're using OBD II ECU's, and i'm just curious how all that works. i'm thinking of eventually moving to an obd ii motor, but still gathering information to see if it's all possible

Just get get an OBD II data link connector from a Grand prix or other 3800 series II car and wire it into the harness, I wire them in to be mounted in the stock location but they can be wired in to be mounted any where. I say get them from GP's or other 3800 cars because some of the other cars like the Sunfires have a different connector it still has the same electrical connection but does not have the holes for mounting the connector like the GP ones have.
For wiring the connector needs +12 volts battery, two wires to ground and the connection to the PCM (purple wire in most cases). Any other wires on this connector are not used in the Fiero swap they are for things like the radio or the heater system. Dan

FieroFlyer, Im in the process of putting a 2001 3.8 SC GTP with the auto trans in my 86 GT 2.8 auto, and would like to know how much you currently charge for a harness and what is your turn around time?

Thanks, Chris

I charge $500 per swap harness when supplied with a 3800 harness to work with and $550 if I have to go buy one to work with, turn around time depends on how many I have to do at the time.
I do not take in more then three harnesses at a time to keep from falling behind so turn around time is from one to three weeks. Dan

I would like to send my harnesses as soon as possible, as I could do it but would rather let someone who has done this before and already knows what they are doing, as is obvious in this thread! Please send me a PM asap. I am sure things will be slower as its the holidays, but I will be working on it steadily and hope to have it on the road in a couple months.

Thanks,
Chris

PM sent. Dan

Hey FieroFlyer. Not sure if you recieved my pm's. Im very intersted in a 3800sc harness as well.

PM sent

DAN
PM sent

Dan where do the 3 wires off the 88 Fiero oil pressure sensor go to in regards to the 3800 harness?

With the oil pressure sensor if the 98 GTP PCM is used you send two wires to the PCM and the third is for the Fiero gauge just follow the diagrams.
For 99 and up series II the PCM no longer gets oil pressure info so only the one wire goes to the gauge unless you want to wire the oil pressure sensor into the fuel pump wiring like the Fiero did. Dan

Will the fuel pump operate as it should if you don't wire it into the oil pressure switch?

quote Originally posted by Khaos88GT: Will the fuel pump operate as it should if you don't wire it into the oil pressure switch?

Yes, provided the relay is wired in correctly. The wiring scheme used on my 3800SC does not have the extra fuel pump circuit path provided by the oil pressure sensor and it runs fine. The parallel circuit connection to the fuel pump at the oil pressure sensor was originally put there to provide a power back up if the fuel pump relay burned out or it might have been an extra current path to ease the load on the relay contacts. Without it you don't have backup protection but I get around this by carrying an extra relay that I can just plug in if it goes out. Since I use the GTP fuel pump relay and it just plugs into the extra fuze box that is in my wiring changing it is a 2 minute job,

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87GT - 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
87GT - 3.4L Turbocharged engine, modified TH125H
" I'M ON THE LOOSE WITHOUT THE JUICE "

And here I thought the fuel pump wiring on the Fieros went through the iol pressure sensor so the fuel pump would be shut off if the oil pressure drops too low.
For the 3800 SC just run the oil pressure sensor to the gauge through C203 pin E and wire the fuel pump relay as the diagrams show, there is no need to include the fuel pump dropping resistor with its extra relay into your harness as it is not of much use and is prone to failing. Dan

10-4.

MAN IF I HAD THE MONEY I WOULD BUILD A "FORUM FIERO" IN HONOR OF ALL THE AWESOME PEOPLE AND HELPFUL MEMBERS IN THE FIERO COMMUNITY!!!!! Something with like a paint job that incorporates a little bit of what everyone here that helps at is good at like.................. Dan would get a mini wiring decal, Dennis you'd get a like an axle decal, Ryan would get a PCM decal, Lloyde an Enron logo(LMAO, wait losing my money sucks, O well I can still laugh about it)....................Well yall get that idea! I think it'd be cool anyway.

I just wanna say that Dan has been most patient with me and helping me through my swap harness. He has provided valued info and all the people who asked questions about wiring and putting it together also did me a great service. Most of you had the same questions as I did. I am using Dan's method and pulling every pin out and refabbing the harness to suit my needs. I have never OWNED a Fiero befor now, MUCH LESS, ever swapped engines into one. This is my first time for all of this and I am doing it all with the help of a few close friends and family. Thats about 3 people by the way. When my swap is complete, and the car is on the road, you can expect to see my pics posted on here showing my complete and NEAT harness on here and it will be my first one ever completed. If a first timer such as myself can do it and make it look like a pro did it, anyone should be able to follow Dan's instructions and get it right and make it look good.

Thanks Dan! A+!

quote Originally posted by FIEROFLYER: With the oil pressure sensor if the 98 GTP PCM is used you send two wires to the PCM and the third is for the Fiero gauge just follow the diagrams. For 99 and up series II the PCM no longer gets oil pressure info so only the one wire goes to the gauge unless you want to wire the oil pressure sensor into the fuel pump wiring like the Fiero did. Dan

Which pins do the 2 wires go to on the 98 PCM. I have a 97 harness pinned to work with a 98 GTP PCM. I will add them if need be.

quote Originally posted by Khaos88GT: 10-4. MAN IF I HAD THE MONEY I WOULD BUILD A "FORUM FIERO" IN HONOR OF ALL THE AWESOME PEOPLE AND HELPFUL MEMBERS IN THE FIERO COMMUNITY!!!!! Something with like a paint job that incorporates a little bit of what everyone here that helps at is good at like.................. Dan would get a mini wiring decal, Dennis you'd get a like an axle decal, Ryan would get a PCM decal, Lloyde an Enron logo(LMAO, wait losing my money sucks, O well I can still laugh about it)....................Well yall get that idea! I think it'd be cool anyway.

and I get a burning brown bag.

For the 98 GTP PCm the tan with black wire from the oil pressure sensor goes to PCM C2 (clear) pin 19 and the black with white goes to chassis ground. With a three pin sensor like the 88 Fiero used the third wire is for the gauge. Dan

Cool thanks Dan. Theres a e-mail your way from me. Just kind of a "making sure Im doing it right" kinda thing.

quote Originally posted by FIEROFLYER: Not sure if I would called it hacked or not seeing as I am not just cutting wires I am stripping the harness down completely then building it back up from scratch. But if it makes your feel better about your self then we can just call it a hack job, there feel better now. Like I mentioned before I am not saying the way I do things is the right way or the only way, I am just showing how I prefer to do things to give people who want to build their own harness a different way that in the end gives them a nice clean job and to show that any one can do a good job if they just take their time. Dan

I believe what Dark is getting at is that your harnesses use a number cut wires that are soldered together and shrink wrapped as opposed to running a completely solid wire from connector to connector. I've seen your harness and I will say that you do a nice job and they apparently work. This is not to say that your method isn't good as most Fiero swaps use spliced harnesses. The only company that I know of who builds a completely new swap harness from scratch (without any splices) is Fuel Injection technology but they do cost a bit more that yours do.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
87GT - 3.4L Turbocharged engine, modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "