• Hello there guest and Welcome to Modular Fox Mustangs home of the 2V, 3V, 4V, Coyote Modular Mustang Conversion Information Website!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

My First 4.6 Fox Swap, any pointers?

MikeySmikey

Member
Before I can answer your question, I need a little more information.

Why do you want to swap out the stock fox dash?

At first I was going to swap the 98 dash into it because of the gauge cluster, but then I decided it just looked cooler, so reason 2 was born.
Is there a way to do the mod swap and retain the factory dash?

Honestly that's at the bottom of my concerns list. The big things are the k-member and rear axle. If those two things will swap from the mark viii to the fox I'll scrap the dash swap, but if not then I may end up going with the 98 GT over the mark viii.
 

Svt Fox

Well-Known Member
Staff member
At first I was going to swap the 98 dash into it because of the gauge cluster, but then I decided it just looked cooler, so reason 2 was born.
Is there a way to do the mod swap and retain the factory dash?

Honestly that's at the bottom of my concerns list. The big things are the k-member and rear axle. If those two things will swap from the mark viii to the fox I'll scrap the dash swap, but if not then I may end up going with the 98 GT over the mark viii.

You can use the stock dash and gauge cluster. The k member is the easy part. You can also use your rear axle as well, assuming the car has an 8.8 in it. The 7.5 will work too, I just wouldn't thrash too hard on it.
 

MikeySmikey

Member
You can use the stock dash and gauge cluster. The k member is the easy part. You can also use your rear axle as well, assuming the car has an 8.8 in it. The 7.5 will work too, I just wouldn't thrash too hard on it.

I wouldn't mind using the stock dash I just worry about wiring issues. The reason I wanna swap out the rear axle is the width. My buddy put an 8.8 from a later model in his and it looked fantastic.
 

Svt Fox

Well-Known Member
Staff member
I wouldn't mind using the stock dash I just worry about wiring issues. The reason I wanna swap out the rear axle is the width. My buddy put an 8.8 from a later model in his and it looked fantastic.

Not really a huge wiring issue. Your factory gauges work just fine.

Regarding your rear diff, you can change the width by running SN-95 length axles in your current housing.
 

MikeySmikey

Member
is there a wiring diagram on here that wire the 4.6 harness in to the fox dash harness?

That's my question. I've seen it done but most people I've seen that did the swap also swapped the dash because it made it easier to tie the dash harness into the fox. I'm sure it can be done but the later models have very different grounding set ups. And aside from a few most of the swaps I've seen that retained the factory dash had the later model cluster stuffed in there which looked off because of the gaps at the top.

Either way it's a job. Both require modifications to make work, I suppose it's just a question of which does an individual prefer.
 

ponyboy89lx

Well-Known Member
Staff member
i would strongley consider ditching my dizzy setup if i knew the wiring wouldnt be a absolute PIA. but the dizzy does look cool lol
 

Svt Fox

Well-Known Member
Staff member
I don't think there is but I could be wrong.

I am using the stock cluster in my car but I am using a 96 harness. So far it's almost been a "hot and ground" affair.
 

Steve

Member
I'm wanting to know what your end decision was with the dash swap. Did you swap or retain the stock dash? What problems did you encounter??
 

David

Active Member
I love the look of the sn 95 dashes...that's the way I went...I even have blower, heater, and a/c from the mach 1 I bought...which I bought from mpsautosalvage for 3500...the only fitment issue I've ran into is that the stock k member puts the engine extremely close to the firewall...on another note..there are a few years that the 2vs used 8 bolt cast cranks..99-01??? Good luck and keep us posted...
 

FuturaGuy

Well-Known Member
Staff member
is there a wiring diagram on here that wire the 4.6 harness in to the fox dash harness?
Found this thread and hope people are still interested. I had to make my own harness but it wasn't that difficult, just tedious.

http://www.modularfoxmustangs.com/community/threads/wire-harness.400/

I put an '88 dash into a '79 Futura that never had fuel injection to begin with, so the easiest course of action was to strip all the wiring forward of the firewall and use the Modular harnesses instead. The only modification to the Modular harness was wiring it for four headlights and moving the battery to the trunk. I also made provision for creature features like power windows, mirrors, and door locks.
 

Attachments

  • Wiring2.pdf
    62.8 KB · Views: 137

el_87fox_negro

Member
Donator
So on the modular engine if I just pin out what I don't need it should work? Ls engines have a stand alone harness when u keep the stock parts... Is the modular ford engines the same concept?
 

FuturaGuy

Well-Known Member
Staff member
So on the modular engine if I just pin out what I don't need it should work? Ls engines have a stand alone harness when u keep the stock parts... Is the modular ford engines the same concept?
Modular engines don't have a stand alone harness. The ECU and other relays and components are integrated into the rest of the wiring for the car. It's not plug-and-play.
 

el_87fox_negro

Member
Donator
This is my first Ford swap, never really attempted this with a ford but I've done plenty ls swaps... I'm excited about this swap but I need to do plenty of research.
So can I keep my fox harness for my lights n join the 2?
 

FuturaGuy

Well-Known Member
Staff member
This is my first Ford swap, never really attempted this with a ford but I've done plenty ls swaps... I'm excited about this swap but I need to do plenty of research.
So can I keep my fox harness for my lights n join the 2?
If you plan to keep your existing Fox wiring, what you have to do, in effect, is cut down the Modular ECU harness and make it a stand alone to connect to the rest of the Fox. Others on this board have done it, so they can better tell you how to do it than I can. My situation was different because I put an '88 dash into a '79 and those two systems were not compatible, so it was (relatively) easier to just strip out the '79 wiring under the hood, use Modular wiring for everything and connect the '88 dash to the Modular wiring.

That said, you have to determine a power source for the ECU and find every circuit that goes from the engine back to the ECU. With a non-California system there are 66 wires that come out of the ECU. Most go to the engine and transmission, but some go to the Constant Control Relay Module (CCRM), the fuel pump relay, or the fuel pump resistor. You need the wiring diagrams for your Fox and the donor engine, and then you have to trace each circuit individually to determine how and where to connect to your Fox wiring. I copied the pages of the Modular wiring diagrams, put them in a loose-leaf binder that my then-wife called "The Sacred Scripture" because I spent so much time reading it, and highlighted with a yellow marker pen the circuits I had to use. My last bit of advice when you actually do the wiring is to write down everything you did. You can't remember it all, especially later if you have to troubleshoot your system. You've got your work cut out for you but best of luck and post often to let us know how you're progressing.
 
Last edited:

el_87fox_negro

Member
Donator
That's great advise man... I'm excited to figure all this out :)
I'm getting the harness in the next week or so... I've never done a ford harness so I'm super excited. Thanks for the help I'll look around here to find who's done this already.
 

el_87fox_negro

Member
Donator
That's great advise man... I'm excited to figure all this out :)
I'm getting the harness in the next week or so... I've never done a ford harness so I'm super excited. Thanks for the help I'll look around here to find who's done this already.
 

whiteponygt

Well-Known Member
That's great advise man... I'm excited to figure all this out :)
I'm getting the harness in the next week or so... I've never done a ford harness so I'm super excited. Thanks for the help I'll look around here to find who's done this already.
Your in for a treat I love Ford to death but there is so much excessive wiring and splices in the harness,if your not careful it's easy to lose yourself in it
 
Top