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Need help! Engine harness 97 GTP

B

Bradh77

New member
Hello guys , I'm new here . I know nothing about the Grand Prix. I have just traded a jeep for a 97 GTP and a totaled 07 supercharged . My sister has a 98 GT. My problem is , the 97 needs a transmission and a engine wire harness. The 98 needs a motor . The 07 has good running gear . Can I use the wiring harness from the 98 for the 97 as well as the transmission ? Also the motor and trans from the 07 to the 98 ? Along with its harness and computer etc..?? I'm desperate to get the 97 going and we are on a very fixed budget right now . My wife and I are in need of getting this car going to take our son to get his chemo treatments once a month , it's a 2.5 hr drive one way to the children's hospital so we need this going pretty quick . Any info will be greatley appreciated !! Please no negative comments . By the way the jeep we traded was non running and the 98 I bought and made it six miles from our house and the motor began to knock , so I gave that one to my sister . Again thanks for any helpful responses .
 


The 97 is a oddball year. Not sure the harness will work. The trans from the 07 is not a direct swap. Many internal differences. Best bet would be to get a harness for the 97 from the j-yard and go from there. The 98 GT trans could work but you will have to swap the diff and axles, as the S/C cars got a different setup.
 
Nothing is really odd about 97. It was the first year of the SC in the W body. GM made revisions on lots of stuff over the years.

You can't put the 07 trans into the 97 or 98 easily. You can't use the injectors, throttle body or fuel rail from the 07 in the 97 or 98. How I would approach this since you need a running car fast and not an issue.

I would put the motor into the 98 because that will be the easiest car to get running reliably and quickly.
1. Swap the exhaust manifolds with the exhaust manifolds from the 98 to the 07 motor
2. Swap the alternator and it's bracket from the 98 to the 07 motor.
3. Get an adapter for the throttle body from SSEillnop here on the forum.
4. Use the 97 throttle body with that adapter in step 3
5. Follow Sseilnop's write up on PCV function to retain pcv properly.
6. Hook the 98's evap hose and connector (part of body of car/wiring harness) to the 07's evap solenoid on the SC.
7. Use the map sensor from the 07 and extend the connector on it to reach the bracket on the rear of the engine.
8. Have someone program the pcm for a supercharged engine with the current transmission you have in the 98.

That should get you up and running fast.

My logic:
The 97 needs the trans from the 98 plus the 07 motor with the above steps to prep the motor plus a wiring harness
The 98 needs the motor and the above steps.
The 07 sounds like it's not something you can save.
 
Hey guys thanks for the info we've spent all day pulling the motor and stuff out the 97 to find the plug in different then the 98 on the trans. However the plug looks the same on the 07 as the 97...those are both super charged cars .. It looks as if it would swap ? Only difference is the 97 has some sort of control module on the shift linkage that the 07 does not but the screw holes are there , to put that module on that trans?
 
you cant use the 07 tranny. best to sell it or trade it for a good older unit.

but like bill said the engine can be used by swapping some parts from the old engine to the 07.
 


The "box" is the pnp. In 07 it's internal and in the 20 pin plug. You can NOT put that 07 into the 97 or 98 without some wiring changes and even then..it has a lot of differences that don't make it easy.
Here's a link to the pnp alignment and wiring in case you pop one off. Keep in mind this is pre 2003 info. 2003 and later is different.
http://www.grandprixforums.net/thre...p-switch-to-a-transmission?highlight=external

Can you post pics of the transmission connectors. 98 GT should be a 4T65E, like the 97 GTP (except HD (97) vs non (98))
 
I don't know how to post pics . The plugs on the 97 and 07 are exactly the same . The 98 is different . The 07 bolted right to the 97 engine and everything appears to be exact . Minus the 97 had module on the shift linkage that is now on the 07 trans .
 
FWIW, it's not going to work. There are pin differences, I'll see if I can remember the name of the guy that did it and I think has it working.
 
Ok I don't understand the pin differences ? I mean the pin holes and everything are exact . The plug hooked right up to it .. I'm not sure what the difference would be . Once I figure out the wiring issue for the engine harness , I will let you know if it worked or not . As for now we are trying to get it to start .
 
No need to let me know Brad. I already know and am trying to warn you.

Pin differences mean.. they moved wiring around. Sure the connector fits, but ...the wires are in different places.
 


Ahh now I understand . Sneaky bastards . Well I'm still trying to get it to start . Would that make it not start also ?
 
I appreciate all the info!! I'm just desperate to get this thing going so we have a dang vehicle .. I hate relying on borrowing one from my brother in law all the time . It sucks when your kid gets sick or something and needs to go to the hospital in a hurry and we have to call and wait etc...so sorry if I'm being stubborn .
 
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Bill I have another question . Dumb as it may sound , could I just switch the pig tails out from each trans ? We took the old one out of the other trans. Would that change the issue or would it still be wrong ?
 
Prove everyone wrong, Brad. Long live the '07 trans! Easiest way to get a running car would've been to get an L36 from a yard, and swapped it into the '98 GT. Would've been up and running in 5 hours.
 


A couple of guys have supposedly made it work. However it's tough to find the info. I think there was recently another guy .. I want to say he used to have a Riviera and now a GP. Anyhow..he made it work as well. But finding the info is tough. If you just plug it in and hope..it's not going to work.

I sort of feel like I had told you at the beginning of the thread how to have a running car in short time.
 
Again , thanks for the information . It's just been a hell of a week here , with the rain and everything else going on . Yes Bill, we are working on getting my sisters car up and running also ( the 98 ) , we are having to swap basically the entire upper half , heads and all , because the injectors are different and you can't just swap the rail . The injectors from the 07 go into the head itself and the 98 went through the intake . I'm going to try the wire swap on the inside of the trans in hopes of this working for me . Or just selling this car , we have discovered that the engine in the 97 looks brand new , it's in great shape . Shows 137k on the odometer , so shouldn't have any trouble selling it at a decent price . Given that the wire swap does not work that is . Anyhow , thanks again for the help . I've called salvage yards here to see if they'd swap me transmissions and they laughed and said we have enough complete cars that we don't need to swap parts . Made me feel like driving over there and punching them in the face for laughing at a simple question , as if I wasn't already having a bad day . Something will come up .
 
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Bradh77 said:
Again , thanks for the information . It's just been a hell of a week here , with the rain and everything else going on . Yes Bill, we are working on getting my sisters car up and running also ( the 98 ) , we are having to swap basically the entire upper half , heads and all , because the injectors are different and you can't just swap the rail . The injectors from the 07 go into the head itself and the 98 went through the intake . I'm going to try the wire swap on the inside of the trans in hopes of this working for me . Or just selling this car , we have discovered that the engine in the 97 looks brand new , it's in great shape . Shows 137k on the odometer , so shouldn't have any trouble selling it at a decent price . Given that the wire swap does not work that is . Anyhow , thanks again for the help . I've called salvage yards here to see if they'd swap me transmissions and they laughed and said we have enough complete cars that we don't need to swap parts . Made me feel like driving over there and punching them in the face for laughing at a simple question , as if I wasn't already having a bad day . Something will come up .
Click to expand...

Wait...if the injectors were in the heads of the engine from the 07, then that was an L32...the supercharged block. Swapping the heads off to the NA stuff is going to decrease power. You should really consider putting the Gen 3 supercharger on and retuning the car. Just saying...
 
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