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Wire harness

FuturaGuy

Well-Known Member
Staff member
I had to make a custom wire harness to connect a Mod Motor underhood wire system to an '88 Mustang dash.

In the '88, there is a bundle of wires that goes thru the firewall with a rubber grommet next to the steering column, then connects to various harnesses in the engine bay. In the '98, the harnesses have connectors at the firewall or behind the kick panel on the passenger side. I had to go into the bundle in the '88, trace each wire individually, and determine where it connected to the '98 wiring. Many of the wires in the bundle go to the connectors behind the passenger side kick panel, therefore the need to jumper across the backside of the dash. I also made provision for some creature features, like power windows, power mirrors, and door locks.

Here's a picture of the completed harness. It's about 6 feet long overall, has 14 connectors (from Motorcraft, Radio Shack, and the junkyard), and I lost count of the individual wires and pins but each one has conductivity to the right place. A lot of thought, a lot of work, and a lot of solder (not to mention burn ointment) went into this harness.

If anyone needs help or wants ideas on how to wire a Mod Motor, send me a PM. I'd like to hear from you.
 

Attachments

FOXMODZO

New Member
LOOKS AWSOME, JUST LIKE OEM..I CAN ONLY WISH I COULD HAVE SOMTHING LIKE THAT WHEN I SWAP MY STANGS ENGINE....
 

FuturaGuy

Well-Known Member
Staff member
In answer to your responses, you CAN have a wire harness like that but you'll have to make it yourself. It wasn't difficult, just tedious, and I wrote down everything on paper before I started making it. I went thru several iterations on paper before the final product.

I won't be selling harnesses to the public. That harness has at least $250 in materials like connectors, wire, and shrink tubing in it, and that doesn't include my time to design and build the thing. At $40 per hour for my time, you couldn't afford my prices!
 

Speedtospare

Well-Known Member
Awesome. I am putting a Mach 1 engine in my 93 coupe. I wonder what the difference between the harnesses will be
 

93Coupe

New Member
do you still have all your notes from tracing wires that you would share or sell? maybe help speed up the process for someone to build their own.
 

FuturaGuy

Well-Known Member
Staff member
do you still have all your notes from tracing wires that you would share or sell? maybe help speed up the process for someone to build their own.
I've still got all the notes and diagrams I made when tracing the wiring and will be happy to share it with you and anyone else who needs it.

I kept everything for 2 reasons. First, if I ever have to troubleshoot the electrical system, I need to know how it was wired and, believe me, you can't remember everything. Second, when I get some good CAD software, I want to copy all my notes and diagrams into CAD, and make 3 paper copies and a CD. One copy goes in the car, one copy stays at home, and the third copy and the CD go in the safe deposit box at the bank. I'm not taking any chances!
 

mvp...

Member
How can I get a copy from you or did you already post it somewhere and I just overlooked it??
 

dave13

New Member
There's an attachment to Post #33 of this link that has the wiring diagram for the harness I made. If you want a better copy, shoot me a PM.

http://www.modularfoxmustangs.com/community/threads/my-first-4-6-fox-swap-any-pointers.1202/
I am doing 96 4.6 2v from mustang to 50 merc. Would this harness work for me? The story behind this is a buddy of mine took on this job, it is to be done towards the end of may he has had car for 6 months. Just called me 2 days ago. I have not done this new of ford yet. In need of help.he has started putting complete car harness in 50 merc, i mean all interior wiring and everything. Just want engine and tranny. Please help.
 

FuturaGuy

Well-Known Member
Staff member
If you're keeping the '50 Merc wiring including the dashboard from the firewall back and using the '96 4.6 wiring under the hood, an exact copy of my harness won't work for you. The basic concept will work, but you'll have make your harness so it mates the Merc dashboard to the Modular wiring. You've got to trace every wire coming out of the Merc and match it to the Modular harness. Also remember that the Merc had a 6 volt system so all the bulbs have to change. The heater motor will need a resistor in series to step the voltage down. The gas gauge sending unit and the gauge in the dash will work on 12 volts. It sounds like you've got a major project going here and unless you're working on it 16 hours a day, you might not get it finished by the end of May. Good luck.
 

dave13

New Member
It had been rodded before. It has aftermarket guages, it really is a sweet ride. Just up grading drivetrain. And at this rate 20 hours a day might not be enough.
 
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dondo84svo

Active Member
Just a update on some info, Just talk to Jeff Dunne of Dunne-Rite Performance. He told me that the Mark 8 harnesses for the foxbody swap will not be ready for purchasing for another 4 weeks, for those who are considering taking this route on their swap.
 

benstein IBC

Active Member
I had to make a custom wire harness to connect a Mod Motor underhood wire system to an '88 Mustang dash.

In the '88, there is a bundle of wires that goes thru the firewall with a rubber grommet next to the steering column, then connects to various harnesses in the engine bay. In the '98, the harnesses have connectors at the firewall or behind the kick panel on the passenger side. I had to go into the bundle in the '88, trace each wire individually, and determine where it connected to the '98 wiring. Many of the wires in the bundle go to the connectors behind the passenger side kick panel, therefore the need to jumper across the backside of the dash. I also made provision for some creature features, like power windows, power mirrors, and door locks.

Here's a picture of the completed harness. It's about 6 feet long overall, has 14 connectors (from Motorcraft, Radio Shack, and the junkyard), and I lost count of the individual wires and pins but each one has conductivity to the right place. A lot of thought, a lot of work, and a lot of solder (not to mention burn ointment) went into this harness.

If anyone needs help or wants ideas on how to wire a Mod Motor, send me a PM. I'd like to hear from you.[/QUO
i really appreciate your willingness to help,, i have a bunch of questions... but i dont know how to pm you im new to this site, im doing a 96 cobra converion to a 92 notchback, was wondering if theres any way you can text me or how can i pm you? my number is 805 236_9821 text me any time, apreciate it... benny
 

benstein IBC

Active Member
I've still got all the notes and diagrams I made when tracing the wiring and will be happy to share it with you and anyone else who needs it.

I kept everything for 2 reasons. First, if I ever have to troubleshoot the electrical system, I need to know how it was wired and, believe me, you can't remember everything. Second, when I get some good CAD software, I want to copy all my notes and diagrams into CAD, and make 3 paper copies and a CD. One copy goes in the car, one copy stays at home, and the third copy and the CD go in the safe deposit box at the bank. I'm not taking any chances!
How can i get a copy of the diagram?im stuck in a rut.
 
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