[Art Cuesta]

I think it’s time for me to reiterate and update some basic information about all versions of the Ford 4.6 computer, reflashes, chip and wiring for any FFR kit build.

Be aware (NOT beware) that these modern 21st century engines and their associated wiring are anything but simple to diagnose when a problem appears, don’t let anyone fool you otherwise. You need factory level diagnostic services by professionals if you want to do anything besides take other people’s advice and throw parts at it (I'm not knocking the forum because it's a valuable resource for all of us) but I think you get my drift.

Computers: There are any number of Computer / PCM (Powertrain Control Module) calibrations for a given 4.6 (let’s say Mustang GT). These calibrations are indicated by the 4 character sticker on the PCM near the computer connector (example: YDH1). If you need a new PCM you must reference this ‘box code’ at the very least and maybe your VIN#. When you acquire a donor or donor pallet it is in your best interest to be provided the VIN#.

If your PCM goes bad it’s important to determine WHY it went bad so if the problem was not the PCM itself but a ground, power or wire issue you correct that to save the new PCM. If the PCM itself ‘imploded’ then a new PCM or possibly even just a reflash (some software glitch) can resolve your issue.

PATS users: If your new PCM or reflash also gave you the factory authorized software upgrade (when available) then your box code will change to the upgraded characters. If your using PATS and they give you a upgraded PCM or reflash - it will also have to be flashed for the upgrade to recognize the PATS (if all work is being done by Ford they will include this, if you have a tuner with the capability to do factory reflashing he would also be able to do this). If not done your new computer or reflash will still be a ‘no start’.

Aftermarket Performance chips: I use DiabloSport for disabling PATS, EGR, EVAP canister, Secondary O2’s, resetting fans and performance tunes. I have found that as Ram posted the chips are more ‘robust’ than just a reflash. What I have observed with the few PCM issues I’ve dealt with that while a PCM may burn up or get a software glitch the chip will survive and be able to be transplanted into your new or reflashed PCM with capability to be reprogrammed for the new ‘box code’. With a reflash it’s gone and you need to pay for those services again.

4.6 wiring harnesses: All harnesses should be intact and in good condition for the best reliability and serviceability. They should all be from the same car, there’s a little play here but you need expert advise to ‘play’, don’t assume.

You absolutely need: 1. The engine harness from your 4.6 modular.

2. The PCM harness with PCM and CCRM / Constant Control Relay Module (this black box contains the PCM power relay, fuel pump relay, fan relays, AC relay).

3. The Battery Junction Box harness (from engine compartment for power and grounds).
Note: One of the really fantastic features of Roger’s 4.6 designs here at WIREDIET.com is the elimination of the use of the BJB harness – think what your engine compartment will look like without this big bulky harness (must use with ABS, Trac Control and Cruise).

4. The Main Body harness – contains all fuel system wiring to the PCM harness. If you want the easy way out on the fuel system use the factory relay, FPDM (Fuel Pump Driver Module), Inertia Switch (fuel pump cut off switch in a accident) and fuel pump with tank, and all associated wiring and connectors all the way to the connection at the PCM harness.

5. From the dash you absolutely need the DLC (Data Link Connector) / OBDII Diagnostic Port and associated wiring and connector to the PCM harness for diagnostics – do not overlook this wiring.

6. No disrespect intended but in my opinion the FFR/Ron Francis 10 circuit revised 5.0 chassis harness is not a good match for a 4.6 build. The reason being a lack of 'hot all the time' and 'switched' power circuits available to address the 4.6 power requirements and accessories most 4.6 builders are planning. I use a 20 circuit EZ Wiring chassis harness and even then with some builders requirements it's tough to have power for everything. Something to think about when ordering your kit and planning your electrical wiring.

If your doing a basic build and aren’t planning on using ABS, Trac Control, Cruise, Instrument Cluster or any other ‘not for running the fuel pump and engine’ feature you will have a MUCH simpler build.

If you decide you want any of these features then you must realize there is NOTHING simple or easy about going this route compared to a basic build - but it can be done. If your just going to stuff all the 4.6 wiring into your build to retain all features that’s fine but it’s a trouble shooting nightmare if someone has to dig into it to diagnose a issue compared to professionally ‘dieted’ OEM harnesses (who's doing them?). Or going another couple of steps further with 'dieted' OEM harnesses fully intergrated with a aftermarket chassis harness as in the original WIREDIET designs of Roger Stine along with the refinements I’ve implemented over the years here at WIREDIET.com).

I’m not trying to position myself as the guy who knows everything about these issues (it's been proven I don't with PCM issues) but I do my best and there aren’t many who have as much experience dealing with OEM harnesses as myself. In closing I just want to open the door for comments and further suggestions by experienced 4.6 builders and novices alike. As I’ve said before on this forum – anyway a builder does his wiring to get a reliably running FFR is fine by me. But what it takes him to get there, how much wiring anxiety it causes him and how much swearing the guy who has to fix a problem later does is in my opinion something worth considering in ADVANCE.

Art

 

[Paul & Colin]

I agree wholeheartedly in my experience with wireing a 4.6 with Art's help and experience.


Paul

 

[LuisL]

My 4.6 DOHC harness just got to Art this week. I'm hoping to see it back in 5-6 weeks so I can move forward with dyno time.

Thanks Art.

 

[rick8928]

I've gotten as far as installing my wire dieted harness all but hooking up the dash. It came back clean, fits great, and Art has been very helpful in fielding both email and telephone questions. Two thumbs up!

 

[G-Pete]

Art, it would be nice to see some before/after pictures of this wire-diet.

 

[G-Pete]

Anyone??

 

[G-Pete]

Hard to digest no pictures here...:shifty:

 

[gtfireftr]

[/IMG]
I do not have any after pictures, but here is a before, and I can personally atest that the after pictures are much easier to digest.....
HTH.... if you are on the fence with regard to Art doing the diet certainly do not even hesitate because it is the best money you will spend on your build.
Considering the ultimate cost of building an FFR Roadster this is a small drop in the bucket..... Good luck.

 

[G-Pete]

I was just looking for pictures so I could eventually justify spending over $1000 (not a drop in a bucket - at least for me).

Thanks

 

[gtfireftr]

My point to saying "a drop in a bucket" was to say that it depends on your overall budget I guess. I looked at it like this, are you comfortable doing the wire diet, electrical on your own, and if so you need to be very confident of your abilities to spend weeks (perhaps months) on the work and hopefully everything works. If something were to go wrong you pretty much have noone to turn to for help. Not the case with the WireDiet. This is just my opinion of course, I felt that the cost was way offset with the technical service that I got from Art. Again everyone is different, and I did not want to make it sound any other way. If you are comfortable doing the work you certainly should and save the money. For me it was money well spent. Also, do not forget the PATS issue as well as anything you want to have flashed out of the PCM will be included with Art. JMHO

 

[ram_g]

G-Pete,

I have many, many pictures of my wiring but no clean "before" and "after" pictures of the consolidated wiring that can be used to get a sense of the totality of the harness(es). Not sure why that is a must have before you get a wire-diet from Art, i.e. what specifically are you looking for? Are you looking to get a sense of how much is reduced? Are you trying to assess the quality of the end product? Something else?

By way of verbal description (you can find any of this description via previous threads, but repeated here):
- Volume reduction is at least 50%. Actually more, because that includes an all-new chassis harness that Art splices on to the factory bits to control lights, etc.
- Everything finished to a high quality - complete with looms, etc.
- Connectors are re-used and all are present.
- Art wires in the starter switch and the headlamp switch but you need to do your own dash wiring for chassis switches.
- Plenty of power circuits available for accessories.

If you want to look at picture(s) of specific parts of the harness please ask and I'll see if I can find a relevant view.

 

[Cobra79]

Perhaps Art or someone else who has used Art's services can supply before and after photos to share with us. I looked but there are none on the wirediet website.
Perhaps something in similar fashion to the irsmachining.com pics.

 

[G-Pete]

Ram, I hear you.

I'm a guy who need yo see before spending that large amount of money. Long story short, I decided to do it my self (like I did so far).

 

[ram_g]

Cool! Is that your own custom fabbed frame? I knew there was someone on here doing that but I thought it was someone else - maybe there's more than one?

 

[G-Pete]

you got a PM...

 

[Fasterpatrick]

No guts, No glory, and not that hard I took a front chassis and engine harness from a Mark VIII and a chassis harness out of a Pickup (same as the column donor) Two wire diagrams and some time,and I made this.....

Take your time you'll do just fine.
Patrick

 

[G-Pete]

Pictures well appreciated Patrick. I studied the wire diagram and came to the conclusion most of the wires can be removed besides the wires to the CCRM and motor harness.

Thanks again.

 

[Art Cuesta]

Sorry guys, I haven't been looking at the forum much lately and when for the first week I could see builders looking without comment I figured my post was just FYI.

I understand cost factors and budget limits when planning one of these builds (after all FFR has designed these kits with budget minded builders in mind). But how crucial is the electrical system in your build to your build?

It seems there's 2 schools of thought and not much in between. 1) It's easy - don't waste your money on someone doing it for you. 2) It's the most dreaded part of the build for those without 'wiring self esteem'.

School of thought 1 doesn't need anything from me. School of thought 2 might want some help. If you have serious concerns about what you maybe getting yourself into by 'dieting' and setting up your wires for your chassis then contact me at WIREDIET.com and will talk about your circumstances, what you hope to accomplish with your electrical system and what your expectations are for connectivity, reliability and serviceability.

Art

 

[G-Pete]

Thanks Art for the offer, I may take you on that ---- thanks again.

 

[KB519]

Thanks Art for the offer, I may take you on that ---- thanks again.

Thanks so much for the outstanding tour of your build, amazing car!