|Customizing Your NG900 or old 9-3 This forum contains all CUSTOMIZING related Q&A's, such as Lights (taillights, headlights, turn indicators, clear corners, etc), Interior and Exterior modifications, Wiring, Gauges and more.|
|11-28-2011, 12:03 PM||#1|
NG900 -> OG9-3 Hatch Swap Information
This post is to detail information on swapping a OG9-3 hatch onto an NG900.
Parts I took from the donor car for my swap:
Interior carpeted panel on hatch
Door sill/scuff plate
NG taillights don't fit properly
3rd Brake Light is LED, so the SID reports brake light out.
Key cylinder cannot be swapped easily.
Door pin is moved from body by striker to internal to the latch.
Door sill/scuff plate does not fit properly.
Lock solenoid cannot be swapped easily.
NG and OG taillights DO NOT mix. The are designed specifically for the rear bumper, hatch and quarter panel fill pieces of each respective model. While the outer tail lights will bolt up and plug in to both cars, they will not look right. There will be gaps and misfitting parts. So this is an easy fix, you will need the inner and outer tailights, as well as the quarter panel fill pieces below the outer taillights.
3rd Brake light:
The 3rd brake light or high mount stop light on the OG is lit via LED's. The bulb check mechanism in the car is expecting 20 watts of incandescent light. Like most aftermarket LED installs, this can be fixed by placing a resistor inline to make up the difference in wattage. I did not calculate the total wattage draw of the OG brake light. I just soldered in the largest resistor I had on hand which was a 10ohm 10 watt resistor. I no longer have a brake light out message. I was able to fit it in the upper trim panel of the hatch.
The NG and OG key cylinders cannot be swapped. The bolt pattern is different. You also cannot order a replacement OG lock cylinder using your NGs key code. I dropped both key cylinders off at a locksmith recommended to me by a local Saab dealer. He swapped the pins between the cylinders so I now have an OG key cylinder that uses my NGs key.
Door pin switch:
On the NG, it's part of the striker plate in the body. On the OG, it's built into the latch mechanism.
You need to pull the wire back from the striker plate to where the hatch harness comes into the drivers quarter. It's needs to be spliced into the black wire with the grey stripe on the hatch harness.
Door sill/scuff plate:
It doesn't fit properly around the latch because of body changes.
Flip over sill plate and lightly warm the plastic with a heat gun or propane torch around where the striker recession is. Snap the sill plate into place, the warmed plastic will conform to the NGs body.
This one was the biggest pain...
First lets lay out how the NG and OG mechanisms differ for the hatch backs.
OG Convertibles operate in a different manner that is similar to that of the NG hatchbacks and NG verts.
Pressing the trunk button on the door or remote pops/unlatches the hatch.
Turning the key in the hatch pops/unlatches the hatch.
Pressing the trunk button on the door or remote unlocks the hatch. Turning the key in the hatch also unlocks the hatch. You can then pull then handle above the license plate to pop/unlatch the latch. The TWICE unit allows you to program if the latch will re-lock after a preset amount of time.
As far as I'm aware, you can't reprogram the NG's anti-theft computer to relock the latch as it was never designed for it.
I did not have an OG around to test and try. So I may have missed something.
I tested the lock solenoid for the OG and found that it likely uses positive polarity and negative polarity on two wires to unlock and lock. I had some issues in my testing, I'm not sure if the solenoid I was using was busted or if I'm missing something with how the system functions. Hooking up two of the wires to + and - made the solenoid actuate. Reversing the polarity made the solenoid make some noise, but it didn't appear to change the lock state. I physically moved the solenoid past some kind of detente. It would now operate using reverse polarity but not hooking it back up normally.
I disassembled the solenoid to inspect how it worked and to check for any broken pieces. Nothing looked out of place. The detente I spoke of before is supposed to be there judging from the way the mechanism seems to function, it's some sort of bypass to allow the key to unlock the latch. I modified the bypass, and the solenoid was then able lock and unlock the trunk by reversing polarity, but, the key would no longer lock or unlock the latch because I disabled the bypass. So if the battery died, and the hatch was locked, I'd have to climb into the trunk and rip off the interior panel to disengage the solenoid so I could then unlock the latch with the key. I decided to undo my modification.
Like I stated earlier, I'm not sure if the TWICE unit is sending some different signals to the solenoid then simple +/- 12 volts as I didn't have one around to test.
What I did have was an aftermarket lock solenoid designed for adding electric locks to a manual lock car. It operates using 2 wires and regular polarity and reverse polarity to unlock/lock. And it also was able to be physically moved without power being applied, unlike the modified OG solenoid. I mounted it where the stock solenoid goes and I had to custom bend a small rod to actuate the lever that the stock solenoid actuates.
You could easily tap into the fuel hatch solenoid at this point to get the proper signal for locking and unlocking with the rest of the doors on the car. But then your remote and drivers door button would not unlock the hatch separately. With all that said, that's a much better position then not being able to use the electric locking at all and having to manually unlock and lock the hatch/trunk with a key.
I ended up making a relay circuit similar to that used when installing an aftermarket alarm system or electric locks. I tapped into the door unlock, door lock and trunk pop wires along the drivers side door sill. I grabbed power from the anti-theft ecu and ground from the lug under the drivers seat. I used some diodes to isolate the unlock relay because it was being actuated from two different sources(door unlock and trunk pop from remote and drivers door button).
The only thing missing is the automatic relock after a preset time limit. Which I don't mind at all. It locks when lock is pressed on the remote or center console and also when the drivers door lock knob is pushed down or the key is turned in the door. It unlocks when unlock is pressed on the center console and also when the drivers door lock knob is pulled up or the key is turned in the door or hatch. In addition, it unlocks when the trunk button is pressed on the remote or the drivers door. I may actually remove the automatic unlocking that's tied into the doors, this way the trunk would only unlock with the remote or button on the drivers door but would still lock when everything else is locked.
Last edited by srp; 11-28-2011 at 02:41 PM.
|11-28-2011, 02:14 PM||#4|
Live, eat, and sleep by TSL
Join Date: Aug 2010
Location: Glen Mills, PA (Phila)
This is like the King James version
Seriously, what I learned here is if you have an OG and need a new hatch, then stumble upon an NG hatch, just look harder for an OG one!
|11-28-2011, 02:44 PM||#5|
I updated the first post with some more information I remembered.
More info and pictures to follow as I remember them.
I needed a new hatch due to rust and I prefer the look of the OG hatch, tails and bumper. And who doesn't like a challenge!
|09-23-2012, 09:48 PM||#6|
I am looking to do this to my ng900 and now it looks like a huge challenge.
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