Spec Boxster Wiring Harness clean-up?

[986FortyEight]

So I've had no time to work in the car this
Past week but with a nice 75F this week-end I should be making some progress.
There are a few items (wires and such) I am not quite certain about so invite you to check this thread during the week-end as I will post a few pix and invite You to play "what is this and can I lose it?".
A good example is the one wire (looks like ground) that travels under the emergency brake and dives under the center tunnel through a rubber grommet. My guess is: ground to the fuel filter, and should probably keep that to be safe. The pix of most SPB builds out there show no wire there. Thoughts?

[trygve]

Originally Posted by 986FortyEight

...
A good example is the one wire (looks like ground) that travels under the emergency brake and dives under the center tunnel through a rubber grommet. My guess is: ground to the fuel filter, and should probably keep that to be safe. The pix of most SPB builds out there show no wire there. Thoughts?

You are correct, it's the ground wire for the fuel filter. I think Brad told me it's not necessary. And you'd think it would be possible to ground it under the car somewhere also. I just fed it cleanly to the nearby ground pin on the passenger floor pan (which on my car was never used for anything, unlike the driver side) so it doesn't get in the way of stuff on the driver side floor like the rails or belts.

I only have 1 cable running along the center tunnel now, and that's the thick cable that goes to the engine (probably the battery cable going to the starter?). Everything else that used to go down the tunnel channel is gone -- parking brake lever sensor, window & heated seat switches, oddments tray alarm sensor, ashtray light, etc., all gone.

[986FortyEight]

Originally Posted by trygve

You are correct, it's the ground wire for the fuel filter. I think Brad told me it's not necessary. And you'd think it would be possible to ground it under the car somewhere also. I just fed it cleanly to the nearby ground pin on the passenger floor pan (which on my car was never used for anything, unlike the driver side) so it doesn't get in the way of stuff on the driver side floor like the rails or belts.

I only have 1 cable running along the center tunnel now, and that's the thick cable that goes to the engine (probably the battery cable going to the starter?). Everything else that used to go down the tunnel channel is gone -- parking brake lever sensor, window & heated seat switches, oddments tray alarm sensor, ashtray light, etc., all gone.

Got it. I agree on the comment regarding grounding in the direct surrounding of the filter.

So when removing all the security stuff (alarm horn, dash LED,
Sensors...) is there anything special that needs to be done in order for it to not
Become a Problem or is the immobilizer just needing to see the key code and nothing
Else matters?

[Jittsl]

I ended up completely eliminating the immobilizer but prior to doing so it came down to only nine wires (from memory) that absolutely had to be there and they were earth and power wires (switched, unswitched and delayed -terminal 86??), a few wires that ran up to the sensor coil at the key and a couple that ran back to the ECU. All the others that came from various sensors or to hardware were redundant.

If you read down the list of them on the wiring diagram in your Bentleys you'll pretty quickly be able to put them into three buckets:-
1) going nowhere (ie you've already removed whatever was on the other end)
2) going god knows where (ie disappears into the ECU for unknown reason)
3) going somewhere obviously required (ie power, earth, decoder etc.)

1&3 are easy to deal with and 2 i tended to leave alone. If you get to the point where you don't know what you are cutting it might be worth cutting one at a time and checking you are still operational in between.

[Kroggers]

Originally Posted by Jittsl

I ended up completely eliminating the immobilizer

Any more details on how you did this, I thought the car would not start if you remove the immobilizer from the car?

[Jittsl]

There is a company here in Florida called the ECU doctors who can remove the immobilizer function from the silver box that contains the ECU. I have no idea how they do it but it allows you do away with the immobilizer box and ignition key altogether (two less things to o wrong and a few pounds saved). Brad may be able to explain it better.

[Kroggers]

Originally Posted by Jittsl

There is a company here in Florida called the ECU doctors who can remove the immobilizer function from the silver box that contains the ECU. I have no idea how they do it but it allows you do away with the immobilizer box and ignition key altogether (two less things to o wrong and a few pounds saved). Brad may be able to explain it better.

So all you do is send them your ECU and they do some magic to it? Or does it do away with the complete relationship between the parts - so they could do it to any ECU that you then install in the car?