wives hate the "while im in there syndrome"

as per your ews, you forgot an ews location to swap. it is the one lil box that the ews key ring sensor plugs into. Its located under the drivers side dash near the steering column.

You only have to swap that if you swap out the antenna ring. If you use your old antenna ring, use your old receiver.

Update:
I received the harness in the mail. Looks very similar to my original except some relay colors are different. My original harness is from a 97 M3/4/5. The new harness is from a 98 M3/2/5.
I will post some photos shortly. I want to remove the fried harness first and lay both harnesses on the ground and compare them side-by-side.
I also noticed the original harness has 3 relays (next to fuse box). The new harness has the same but an additional relay (light green) next to DME plug.

I was finally able to pick up a S52 OBD2 harness from bfc :smile:
If you have a minute, please take a look at the videos I shot of both harnesses. I'm trying to compare them to ensure I'm on the right track and not burn another harness.
In summary:
My original harness was a 1997 M3/4/5.
My "new" harness is from a M3/2/5.
Three main differences between my harness and the new harness:
1) Extra relay near DME plug on the new harness;
2) Different cable arrangement on new harness in relation to where it gets bolted to fuse box (near 3 relays)
3) Different cable arrangement on new harness in relation to emission fan.

http://www.youtube.com/watch?v=yG_lV...el_video_title

http://www.youtube.com/watch?v=CtVHZ...el_video_title

http://www.youtube.com/watch?v=ZMm14...el_video_title

http://www.youtube.com/watch?v=Jtxvl...el_video_title

Please chime in and lend me a hand. I haven’t installed the "new" harness on the block yet until I'm 100% sure I'm on the right track.

Thank you very much.

I think your first harness might have melted due to grounding one of the positive wires.

The burn was caused by an incorrect relay. I mistakenly swapped out 2 relays. The first relay (emission’s secondary fan) was removed in order to jump it. I was jumping it as at that time it was believed that particular relay was the fuel pump relay. When the test was performed, the fan started up. When putting it all back together, I think I inserted an incorrect relay (one of the light green relays that lay next to this relay) and when that happened, the brown wire in the middle of the emissions fan relay melted away. The following video explains what happened.
http://www.youtube.com/watch?v=KW1CQ...el_video_title

Its been a while...
Finally got some time and installed the 98 harness into the ti. After messing with it a bit, I finally got a check engine light on my dash. So, looks like the computer was not getting any power.
The culprit all along was a poor connection at the battery. Somehow the thin red wire that goes to the (+) battery became loose and it would allow the car to crank but not start. The thin red wire runs along the thicker red (+) cable but it has a fusible link, my guess to protect the computer.
Anyway, car starts! Sounds hostile since I have no exhaust.
I still need to work some things out to get her road worthy, such as:
- Bleed cooling system. She is running at normal temp but the heater is not warming up the cabin.
- Install the heat shields and then install the drive shaft.
- Go to a muffler shop and fabricate something to hang the stock M3 muffler. I'm not planning on anything fancy for the exhaust for a while. Just want to get her running and pass inspection.
More to follow. I was so stocked when I heard her fire up the first time.

PS.
Thank you everyone for your help in T/S my electrical issues. This forum is awesome and I would've never dived into something like this without your support.

Update:

Exhaust (downpipe???) up to and including the cat converters is installed. It is just being held by where it's attached to the headers. I just wanted to kill the sound a bit so I could drive it.
Drive shaft is on. I know the DS subject has come up a lot and this is what I ended up with. My original M3 sedan DS is the 6 bolt, so it's useless in this project.
I went ahead and purchased a 4 bolt M3 DS on the forum. However, it did not fit. Instead, I used the front half of M3 (4 bolt) and second (rear section) half is from 318ti. I'm using the S52 with the M3 tranny.
I drove around the parking lot. Still need to bleed the cooling system and top off the P/S reservoir.
Second gear is hitting something. Well, the tranny is fine; it’s the lever when in 2nd gear that’s hitting the DS. Shifter is also from the M3 so I was under the impression I didn’t have to modify the shift lever...

More to follow...

Took her on the HWY today, now I have a headache! I really need to address the exhaust. Maybe the fumes are going into the cabin.
No vibrations or anything out of the ordinary. I did notice how nose heavy it rides! Hopefully this is something someone can give me some advice.
Still pending:
A/C
Exhaust

are you running M3 6cyl springs in the front?

nope. stock 318ti suspension all around. I do have the donor's M3 front and rear suspension.
Not sure what I'm going to do:
Front M3 suspension; leave rear as 318ti;
Front M3, rear MZ3;
Bilstein/H&R combo designed for 318ti;
Just do a front Bilstein/H&R on the front M3 suspension:
???

That extra 150 lbs on the nose of the car is noticable... I just went with ti H&R/bilstien all around combo, and Eibach sways f & R as well... Very happy with the setup, but will swap in some 6 cyl front struts down the road...

Update:
Still need to find the right hoses to hook up the a/c.
Also, 1st gear is useless, plus only the right wheels has power (not LSD).
I have Racing Dynamics RGR 17X8. I wonder how wide I can go in the rear?
If not, how wide on a set of countours?