3800 swap harnesses (Page 12/20)
Khaos88GT DEC 28, 02:52 AM
Will the fuel pump operate as it should if you don't wire it into the oil pressure switch?
Dennis LaGrua DEC 28, 10:15 AM

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 "

FIEROFLYER DEC 28, 11:04 AM
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
Khaos88GT DEC 28, 12:50 PM
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.
Flyboy81 FEB 02, 11:33 PM
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+!
Flyboy81 FEB 03, 07:40 PM

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.
darkhorizon FEB 03, 07:59 PM

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.
FIEROFLYER FEB 03, 09:22 PM
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
Flyboy81 FEB 03, 09:59 PM
Cool thanks Dan. Theres a e-mail your way from me. Just kind of a "making sure Im doing it right" kinda thing.
Dennis LaGrua FEB 04, 09:33 AM

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 "