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auto-to-manual swap wiring harness modifcations?? HELP!


Guest TurboSedan

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Guest TurboSedan

what needs to be done to the automatic transmission wiring harness when doing a 5-speed conversion? i specifically need (or at least want) the backup lights to work and i think there is something about making the ECM 'think' that the car is always in gear so as to avoid the Park/Neutral rev limiter....or something like that :think:

 

the only thing i've done so far is lengthen & re-route the VSS wires.

 

there seems to be 3 different plugs on my auto (TGP) wiring harness and i have no idea what they are for. two of them are black & green and they are near the starter/bellhousing ground stud area. one of them is round and the other looks like a MAP sensor connector. then there is another plug below the brake master cylinder area that is black & blue and i think that one is the gear selector indicator? ugh i'm kinda lost here :oops:

 

even though i did the 5-speed conversion like 3 years ago, i have always used a 3.1/5-speed specific engine wiring harness so i didn't have any wiring issues to worry about; it was plug n' play. now that i've turbocharged my 3.1 with TGP parts (including the TGP auto wiring harness of course) i need to know what modifications need to be done.

 

any help very much appreciated, thanks

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The round plug on the front controls TCC lockup and the shift solenoids. The plug you referred to under the master cylinder is the P/N switch. I dont know how to adapt the harness, I just know what those two plugs are.

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Your transmission switch needs to be in D I believe.(Kenny would know) The trunk release (if you have it) and back up lights are routed through that switch as well. If I remember, I'll check out the wire colors and let you know. If not, You can check it out when we get there on the 19th.

 

Edit, yea, the harness for the auto tranny you just leave disconnected. I never thought about that one. :lol:

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Luke didn't you get the Back-up lights to work on the TGP? I never bothered.

 

The large connector is the TCC and such. Disconnect and leave hanging. It is not an electronic tranny so the ECM really doesn't care what is happening. It relies more on the VSS for corrected idle speeds and such. That you will need to change in the MEMCal anyway (throttle follower, idle speed (IAC counts) when in motion, Manual tranny flags that need to be set, etc.) Jeff may have some insight to those settings, but Mick at http://www.gmpcm.com has a list of initial corrections we made when I did the swap on Luke's car.

 

To eleminate the neutral switch there are two very fat (8 gauge?) wires that you need to loop or connect to the clutch pedal switch so it will crank and kill the rev limiter for P/N. I think it is a yellow wire and a purple wire?? :oops: Been a very long time but they are impossible to miss and they are in the mutli-wire plug going to the tranny IIRC.

 

Man it has been a long time, so if I am wrong about where the wires are I apologize in advance! :oops:

 

*edit* Setting the tranny to D is not an issue. But you will have to set the appropriate flags on the MEMCal for manual tranny operation! A stock or modified auto-tranny chip will run like CRAP! It will stall, sputter, and have a very very ugly boost ramp. Hits full boost then flops on it's face after 2 seconds. Will not give boost again until you stop the car and restart it. Idle is too high and spiratic.

 

Loop the P/N wires because if they are connected to the clutch switch it will be defeated as soon as you let out the clutch.

 

Hope this helps! I have 6 beers in me right now and flash-backs of doing the swap are scaring me!! :shock: Can someone give me a HUG?? :lol:

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I left my park/neutral safety switch in park, so that I didn't have to bother splicing any big gauge wires. I had to cut the black/white wire coming out of the park/neutral switch so that the computer didn't think it was in park/neutral so that the rev limiter was gone. I don't remember the colors for the backup lights, but I think they run through the same switch. My trunk pop doesn't work, but that's not a big deal for me as I don't have a remote. I'm probably going to get a remote soon so I guess I better look into that. :roll:

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Guest TurboSedan

 

thanks for the link Sean. i read the article over (very helpful) and i think i have most of it figured out. so i leave the other two plugs hanging but i need to modify the P/N connector. the article says i need to cut the green and orange wires from the P/N connector and splice them to the green & black wires coming coming from the reverse switch. well i got the orange wire but no green wire - only a green/white wire which i'm assuming is the green wire i need?

 

also, what does the orange/black wire do and what should i do with it? the article mentions this wire but no description of what it is for or what to do with it?

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Guest TurboSedan
I had to cut the black/white wire coming out of the park/neutral switch so that the computer didn't think it was in park/neutral so that the rev limiter was gone.

 

ah thank you. i was wondering what the black/white wire was for. my connector has 7 wires and not 6 like the article on 60*V6 describes. so you just cut the black/white wire and left it hanging or?

 

thanks again for the help....lotsa wiring work for me today

 

btw Dan stop by if you can :)

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I was looking at the wiring diagram and I think the wire is orange/black and not white/black like I mentioned above. I don't remember exactly what I did as it was over a year ago. I remember something about the computer being grounded when it was in park/neutral which then enabled the park/neutral rev limiter. I think I just cut the wire so that it wasn't grounded. Look at a wiring diagram and figure it out as I'm not sure exactly what I did. :oops:

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