Spec Boxster Wiring Harness clean-up?
 

So as you can see from the pic I am at the fairly familiar stage in the spec build where it makes sense to take some time and remove the unnecessary wiring.
I have, like most people, a healthy fear of the damages I can cause by touching something I have no expertise over: electrical wiring. Of course that won't stop me from trying.

http://i.imgur.com/ibzGtRp.jpg


So before I just start cutting the excess wire and create a potential fire hazard, I figured I would ask if anyone had some advice on how to do it right.
I know to start the car regularly to verify that it is still operational, but what about the actual removal of the wires? do you trace it all the way to the relays? fuse box? can they be pulled cleanly or is there a need to cut and terminate?

Any help is appreciated.

Michael

50 views and not 1 piece of advice? I know it's not a sexy mod but I know the talent that resides on this forum should be able to offer some sort of insight!

Not much to say on my end! About all I was brave enough to do was cut back all of the car stereo wires, because I knew they had neither power nor signal at that point.

I have heard that you can trace a given unused wire all the way back to the fuse or relay panel and ultimately pull the pin out there. You can also remove lots of unnecessary relays, depending on what accessories have been yanked out.

The ideal endgame includes moving the immobilizer box out from under the seat, along with the front fuse and relay panels, perhaps to the former passenger airbag dash location. Of course, that probably requires getting the whole harness out of the car first to unravel lots of wiring from the bundle. At a minimum, I'd recommend moving the immobilizer box as-is, off the floor, putting it in a plastic bag attached to the door bars of the cage, so it cannot get wet.

Here's a photo of my car during the interior tear-down, when it looked its worst!
http://farm7.staticflickr.com/6098/6...448486d377.jpg
tedious work by bombaydigital, on Flickr

Thanks!
I actually came across that flicker series of pics while scouting the web desperately for more info.
From what I've read, once all unnecessary wires are gone, 4 remaining wires need to be extended in order to relocate the fuse and relay1 boxes to the old passenger airbag spot.
Good call on the immobilizer.
I started to go through the schematics in the Bentley and highlighted all the stuff I can pull out. I also found this video interesting for removing terminals from a connector:
removing terminals on the VW wiring harness - YouTube
It should be similar on the Boxster connector.

Michael,

I start with all door wires, then stereo wires, then move to the HVAC wiring.

I end up with 4 fuses and one relay (fuel pump) at the front.

The biggest mistake I have made is accidentally removing a portion of the brake light wire. It splits off and goes two directions: ABS and brake lights.

Typically I pull 20+lbs out of the harness (depending on options the car shipped with)

The clutch safety switch can be grounded back at the ECU, so.. the wiring can go.

I'll have the TexasSpec site back up in a few days. Right now none of us can recall the admin password for the admin area.. LOL

I successfully removed a full garbage bin full of wire and associated crap (about 30 lbs all up) by taking the following approach:

Start with wires that lead to nowhere because you have removed the thing that used to attach to them ie stereo, heater, airbags, AC, electric locks, windows etc. and simply remove the wrapping off the harness and trace the wire back to its source if you can (usually a switch, a fuse, the immobilizer or the big harness that runs back to the rear). If you can remove it all the way to the point of origin in one go great! If not, simply terminate and wrap the wire wherever you end up (it doesn't matter because you know it doesn't do anything and eventually you'll come back to it). Don't rewrap the harness yet. Instead simply place loose tie wraps around it every foot or so (that way the next wire you deal with can be more easily dealt with). Keep going until you have removed all the wires that terminated at nothing. It will take a lot of effort and a lot of patience but it's amazing how simple you can make the whole system in the end.

The next phase is to study the wiring diagrams and figure out what of the systems that are left you can live without or abbreviate - things like indicators, trip computers, wipers, lights, emmissions crap etc.

The only mistake I made in my process was to cut away a bunch of twisted pair wires that I assumed were speaker cables - turned out the Anti-lock brakes also use twisted pairs so I had to do a little rebuilding.

Not a job for the impatient but lots of fun.

Laurence.

This is also on my long project list, so I will follow this discussion with interest :)

A related suggestion - while you have everything apart, it would be a good time to consider wiring for the things you will be adding to the car. Things such as a transponder, cool suit, trans cooler pump, etc. It will be easier and cleaner to add those now and incorporate them into the revised harness.

When I'm done, I'm using a black split loom mesh in 3 sizes.

3M sells a cloth tape that is nearly dead on (it's a few mm's wider) and can be bought at Home Depot!!

The later 9X7's gave me the idea for the mesh loom cover. They use it throughout the car. I buy it from a company close to the shop called "Orvac".

I wrap the mesh cover every 6-8 inches with one wrap (don't pull it tight) the mesh cover is made to wrap around the wires (think spring loaded)

This picture wasn't taken to show the harness, but you can see what I end up with. This was a BoxsterS not a 2.5 car.

http://www.bradrobertsag.com/pics/016.JPG

I still hate this site.. cant upload pictures.. LAME.

Guys,

Thank you so much for all the feed-back!
Got a couple of very welcomed PMs with additional information, thanks for these as well.
Just ordered a bunch of parts (S oil cooler, 3rd radiator kit, low temp thermostat, new water pump, 3qts accusump to replace the seizing one...). This means that I have 1 week to get through the wiring fun before I get compelled to switch to the new shiny stuff!

So Brad, 4 Fuses and 1 relay seems extreme! looking at the diagrams I listed everything that seemed safe to pull but several relays appear to have dual function. Is that result achieved just by attrition or do you re-route some to the 2nd relay panel in the rear?

Sounds bad... you mean you love the community but feel the tool could be improved? :)
Have you tried "Password123" for an admin pw? :D

I ended up with 3 relays. Fuel pump up front and 2 engine system relays at rear.

I also have a few more fuses than Brad. 1 each for wipers, lights (not really needed), brake lights, fuel pump, unswitched power and switched power - 6 total. I then added 4 that for accessories - cameras, Coolsuit, transponder and my face level blower fan. In my case a new fuse box is located on the end of the dashboard so that it is easily accessible and the original is gone along with the relay box.

Sounds closer to what I expect to see when I am done.
The new fuse box you mention, did you go the painlesswiring.com route?

No. I just bought 2 inexpensive universal fuse boxes (the sort with a single input connection and 6 fuses with spade outputs) on ebay. I then wired one as switched from the ignition key and one as unswitched from the distribution box and then utilized as appropriate for the purpose. Switched fuses go to 1.Engine (DME etc.) & ABS, 2. Fuel pump, 3. wipers, 4. lights, 5. brake lights and 6. transponder. Unswitched to 1. engine, 2. inside fan, 3. Coolsuit and 4. cameras. 5&6 are spare

If I had a clue how to post a photo I would do so but alas I am clueless when it comes to these new fanged technologies.

Laurie

when preparing your response you should see a "attach a Photo" option below the text box. It allows you to upload a pic providing that it is no bigger than 2MB.

The other option is to upload a pic to a 3rd party pic site like imgur: the simple image sharer and just share the link to the pic. imgur actually offers the right code to embed in whatever interface you are using.

Michael, I just realized that you are in Austin. I'm in San Antonio. You are welcome to drop by any time and have a look at what I have done. Email me on Laurence.jitts@att.net if you would like to do so.

Laurie

I set the wipers up so they are removable in 5min. Quick disconnect at the motor. The relay/wiring stay with the actual assembly. It leaves me with one speed.. but experience has shown me there is no need for 2-3 speeds. I wire the *fast* speed to a toggle switch on the center face plate.

One relay "at the front" for the fuel pump. Still need the rear relays (as Jitts pointed out)

I don't have a lot of people out here running cool suits and the such (we don't see the heat)

I wire the transponders off the heater wire for the windshield washer bottle (it's key on) *Some* of my customers ask to have the transponder on a switch..

Likewise the wiper in my car (I've only got one - I cut he passenger side off). Single toggle switch / single speed / single wiper/ no relay. Due to carefully placed hole in plastic shroud (to allow access to one of the two bolts securing the motor assembly) the wiper and motor are in or out in a few minutes. Similarly my lights are toggle switch / high beam only / no relay. Both have a new harness made up for them. Simply - switched fuse box - toggle switch - wiper motor (or lights including tail lights) - earth. The stalks are long gone.

I managed to get the TexasSpec site back up and running tonight :)

"Cool", says the newest user.

Woohoo!!! That's great news! Now the key is getting some of that activity/traffic level from the boxsterspec days back.

That's very kind of you and i will take you up on the offer!
I used to live in Southlake about 3 miles from the Amonds and their porsche centric garagemahal. But now in Austin, things seems quite limited in terms of SPB racers. May just be getting to find the right venue!

I know of at least one other Specbox in Austin but as far as i know I am the only one in San Antonio. look forward to seeing you here soon.

One of my customers just moved to Austin :) I'll be bringing his car out for events shortly.

He is CEO of fairly new startup so he doesn't have a lot of free time right now, but will when he starts to get a handle on the business.

He has been racing for 10 years. Started off in PCA TT, then moved to 944Spec where he won back to back championships, then moved to BoxsterSpec in 06, took 3 years off to run a large corporation in Shanghai, came back raced spec for one year, then won the 2012 POC BoxsterSpec championship :)

We *hope* to run in the top 10 with the Texas guys :)

I'll never forget the day Chris Amond called me "hey, what do you know about this BoxsterSpec thing"? lol This was mid to late 06. I've considered the Amond family "friends" since the mid 90's when they came to my shop one day in Arlington.

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?

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?

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.

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

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?

Yes. You send them your Box and they do something and then send it back. Or they can send ou a modified one (as they did in my case). After modification there is no longer a dependency on the immobilizer at all. Mine could be fitted to any 2.5 986 and the car would start.

Eric from HRG in California got DQ-Ed for the season after scrutineering saw the Immibilizer was gone and the ECU was no longer factory.
Of course he also had a start button and the whole steering lock was gone.
I guess you just need to make sure your local scrutineering will be ok with that mod.

What did they charge you for the new box?

Honestly can't remember but it wasn't cheap. Drop them a line. If you can't find them Let me know and I'll find their details.

Mine also has the lock etc missing but I've had no issues with PCA s far. I also tend to finish fairly low down the order so I don't think anyone is too concerned about my car having any great advantage.

Here is the link to the thread where Eric goes over the process:
Steering Lock & Push Button Start

Cool, thank you...