Ford Performance Multi-Port EFI Wiring Harness For 5.0L H.O. Engine Swap

Ford Performance: M-12071-A50
MSRP: $755.00
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Ford Performance Multi-Port EFI Wiring Harness For 5.0L H.O. Engine Swap
Ford Performance

Product Description

Ford Performance Multi-Port EFI Wiring Harness for Mustangs with a 5.0L H.O. Engine Swap.

Need a new wiring harness for your Mustang with a 5.0L H.O.? Or perhaps you have a Hot Rod or other non-Mustang vehicle with a 5.0L H.O. engine and you need a wiring harness for it? Well, we have the ticket for you!

This is a complete harness from the PCM to the injectors. One of the most common requests regarding the Electronic Fuel Injection Wiring Harness has been for a cleaner appearing harness and a simpler method to make connections. Ford Performance has heard your voice! Ford Performance has tried to be as thorough as possible in developing a product which will provide you with the cleanest and simplest wiring harness on the market.

Features and Benefits:
- Revised for simplified installation: now only a single connector is needed for all required connections
- Kit consists of a single harness with vital connections for injectors and O2 sensors
- Fully loomed, from PCM to all sensors and injectors, to save time on installation
- Usually takes less than an hour to install
- Direct fit on 1986-1993 302 H.O. engines
- Can be easily adapted to many other Ford V8 pushrod engines
- Compatible with engines using both H.O. and non-H.O. firing orders
- Provisions are included for electric fan control output
- A compact fuse and relay box, "Check Engine" light, and all necessary grommets are included

Please Note: A PCM from a 1989-1993 5.0L H.O. Mustang is required but is NOT included.

*This part has been designed and is intended for off-highway application only. Installation of this part on a vehicle that is driven on public roads may violate U.S. and Canadian laws and regulations relating to emission requirements and motor vehicle safety standards.

If you're looking for parts for your Mustang, you should start by looking at the variety of Mustang parts that CJ Pony Parts offers from Ford Performance. By buying your Ford Racing parts from CJ Pony Parts, you know you're getting your Mustang parts from a reliable, reputable dealer, since CJ Pony Parts is a Top 10 Ford Racing Dealer and has been for the last 10 years. When you buy your Ford Performance Mustang parts from CJ Pony Parts, you know you have a winning combination--this means dependable, quality care for your Pony.

Order a Ford Performance M-12071-A50 Multi-Port EFI Wiring Harness for your Mustang with a 5.0L H.O. Engine Swap from CJ Pony Parts today!

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Installation Instructions

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Product Reviews

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Ford Racing Multi-Port EFI Wiring Harness For 5.0L H.O. Engine Swap is rated 5.0 out of 5 by 1.
Rated 5 out of 5 by from Basics to make the car run and nothing else Brand new Ford quality wiring harness, The install manual is very helpful and so is Roy at the Ford Racing Technical Support. They used almost all the original wire color markings so looking at the new harness the wires matched up well with my old harness. Gets rid of those nasty big salt and pepper 10 pin connectors. Very clean look and solid connections with no broke tabs. Remember to always disconnect your battery before starting. What is not included is the Low oil sender, Air bags and Charcoal Can Relay. Fords Idea was that this harness was made to go into any Rod and make it EFI that is if you can find a computer. But if you have a fox the wiring harness is very similar to our original harness. Its just missing the above mentioned items, no biggy being that I have a 7 qt. pan with no low oil sender and a non air bag steering wheel and the charcoal air can still breathes and I do not have it attached to my intake. The old a/c cut relay switch will be deleted, so will the ECC relay and fuel pump relay. They are now all located in the new black box. Cleaning up more wires under hood. I was able to reinstall the new harness into my old firewall grommet, just remove it, slice one half of it and put in the new harness and install. You will have to extend some wires and will have to reuse some of your old harness mainly the brown 8 pin circular connector that was located on the drivers side by the brake booster this will give connections to the 12v Start, 12v Start Run. and tie into your stock Tach, Oil pressure, and temp gauges. You can tie the wires into your aftermarket gauges but you will still need the 12v.start and start run feeds. All the wires are individual flagged nice, but you may want to write down every wire name in case you lose one of the flags. I built a new wiring harness using the new 12v. Start,12 RUN Start wires along with the tach wire. Ford supplies connections to your temp and oil pressure, but you need to extend them with your own supplied wire. Put these wires all together and shrunk wrapped, taped and connected them to my old 8 pin connector. I ran these wires out thru fire wall with the main harness and put on the 8 pin connector. All the supplied wires in the new harness are plenty long. You need to relocate the inertia switch near the kick panel pass side, because the inertia cable is short I mounted mine on the frame of the center console. the end connector plugged right into the inertia switch. Just remember when you remove it from the trunk you have to jumper the wires or you will not get power to the fuel pump great place to tie in a kill switch to stop those thieves. I mounted the black fuse/relay box on my cabin filter box. see pics. They do not give much wire to the 60 pin connector and there is not many other places to mount it. You will need to use there Check Engine Light and mount it some where. May be you could tie into your existing light, I just used there supplied light. This is spelled out in the manual. As the Black box unit and car will not work if you do not. My clutch safety switch still works. Cruise still works, Next when you tie into the DG/Y fuel pump power wire in one of the green square connectors near the computer area, it bypasses the relay under the seat, and goes to the fuel pump, no need to splice into anything under the seat, just remove the relay, this will disconnect your feed from the battery. The power is supplied from the fuel relay in the black box. The new OBD1 port is located in the kick panel as seen in my picture. Make sure you solder all your connections shrink wrap and tape everything There is 2 grounds or negatives 1 goes to the battery and the other goes to the ground screw on the frame by the pass. side kick panel. I connected both my negatives directly to the battery. I did not want any flaky grounds. Keep all your existing grounds like the one going from the motor to the firewall and by the windshield washer on the fender, and of course the negative going from the battery to the motor. My method of connection was to tin the wires and stripped the plastic off butt splices filled them with flux, crimped the tinned wires and soldered the at each end from butt splice to wire. For soldered, crimped, and soldered termination. I shrunk wrapped the connections and used a oversized shrink wrap over all the connections. There is only 1 power connection and that should be tied to a 50 amp fuse. The only real problem I had was pin 19 (Keep Alive Memory) in the 60 pin connector was not fully seated in the harness and was not making a good connection to the computer. My car may differ from yours and good luck. Remember protect your computer there are not many left. This worked for me but maybe not for you. Good Luck!
Date published: 2015-10-19
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Product Questions

I have a Mercury Mountanier 1997 model with a 302 and aod transmission. Want to put it in a 67 mustang. Will harness work with mercury PCM ?? 

Asked by: Bear 32
The vendor has not provided any information regarding cross-fitments of this part to any other model then what is listed.
Answered by: CJPP Dave
Date published: 2016-04-20

Doing a 69 vert restomod thinking about using a 91 5.0 H.O five speed, will this harness work with the original harness in car? Is it a stand alone harness or would I need something else?

Asked by: 69vert
There will be some additional wiring that will be necessary, but this harness will handle the bulk of the wiring that is necessary for that engine swap.
Answered by: CJPP Dave
Date published: 2016-03-07

I have 81 mustang LX 4 cylinder foxbody w trunk that I put a 302 out of 86 F150 carbureted, automatic. My harness was melted will this harness work for my needs.

Asked by: TimTat2
No, this is for a EFI 5.0
Answered by: CJPP Dave
Date published: 2016-03-07

Is this harness like the old FordFuelInjection. com harness that was available for a while? Just what is needed to install engine and PCM into a classic mustang? Will I need additional harnesses and such? I am putting a 89 5.0 H.O. with a tubular GT40 

Asked by: badmfer65
First off, I would think it is not like those. That harness was made for mustangs and carried other wires for other accessories. But in your case less is better. Just the basic EFI inputs are in this harness. Now, not knowing what is left in your classic mustang you need some inputs like ( key on run), and( Key on Start), Also you will need your alternator circuit to your starter relay. The instruction manual is very good and Ford gives you extra wire in the harness, only complaint is not a lot wire between the black box with the relays and the 60 pin connector to the computer. In my case, with a 91 mustang I tried to keep my computer in the stock location and it did not leave me a lot of options to mount the black box. This box has relays and fuses and may need accessibility. Good Luck. NANotch
Answered by: NANotch
Date published: 2016-02-26

Greetings, I picked up a 5.0 ho from a 91 t-bird, with the remote t.f.i. Now to use this harness do I need to switch out the pcm, and the distributor to a 93 and older mustang? Any help is welcomed. Thanks for your time and effort. Dave

Asked by: 951f100
First off, to answer your question's, you should be able to use the PCM from the T-bird. This is a 60 pin style harness, and from the best of my knowledge 89 thru 93 mass air Fords, they basically used the same computers. The differences being how many pins were used. This is a very simple, basic, harness, to make any 302 motor into a EFI. The instruction manual will tell you what sensors are needed, with the parts numbers from Ford. Knowing that, any 89-93 302 distributor with Thick film ignition mounted on the distributor will work. I have read about remote mounting of the TFI. for cooling purposes, and that became standard on 94-95 mustangs. Miata's with 302s needed them remote mounted too. Hope this helps. NANotch
Answered by: NANotch
Date published: 2016-02-26

Could this kit with little modification be integrated in to a 93 F150 engine 302 Aod?

Asked by: mahorton
yes this is a universal kit for the 302 designed to support a swap.  you will at least need the mustang ecu for a manual transmission.  you may need to switch other parts also.  the aod is a pressure controlled trans so it will not need any wiring or controls.  however the aode which is similar and commonly confused with the aod will need a stand alone controller with this harness. as for the vehicle connections you will be on your own with a good manual or some sort to figure it out.
Answered by: tom cjpp
Date published: 2016-01-12

NA Notch, Where do I tap in for the fuel pump? Do I use the green 8pin harness near the as a tap? My 88 Mustang shows tan/light green at this green harness, correct? I thought this goes to the relay under the drivers seat though. Thank you for any help.

Asked by: tonawawa
Yes I did tap the green wire in the 8 pin connector that's in the pass side kick panel. Question 2. And that's what I thought to, but going to the relay I believe it comes from the relay. because I had cut out my fuel pump relay and ran the fuel pump wire (green) from the new relay box to the black/pink that I thought went to the tank. But when I hooked up the battery, the fuel pump came on and would not shut off. Like I back fed the circuit. So then I hooked it to the green wire at the old relay and it worked ok. Or in your case Tan/ light green. So in summary, I think all you need to do is pull the fuel pump relay out, with out cutting the wires. Then find out if the tan/light green leaves your old fuel pump relay and tone out with a meter to the green 8 pin connector. If it tones out then cut the wire just before the connector and splice it there. Then you keep the connector operable and most of your splices in the kick panel area, instead of running the fuel pump wire under the seat. This was probably the hardest part I had to figure out. Ford Guys were helpful but I had to find this one out on my own. Also my car was a 91 and wire colors change from 88 to 91. Also ford did a good job keeping colors the same in the new harness. That's what made me think of trying the green wire at the old fuel pump relay. There is some good wiring schematics out there. but none seem to show how the whole fuel circuit runs thru the car from origin to termination. Like I did not figure out how my neutral safety switch worked, it just did. And I put in a push button switch in my trunk, where the inertia switch was so when I leave the car I can disable the fuel pump or crank the car with out it starting. Or leave that switch and just cut out and connect the 2 wires of the new inertia switch, its just a switch loop. Hope this helps but it sounds like your on the right path.
Answered by: NANotch
Date published: 2015-12-31

My harness (ford racing) has a fuse box, and when the ignition is  switched on the green lights cycle in the fuse box, now the one listed a/c has no power and the fuel pump does not cycle and no spark. what is the a/c mean , car has no ac installed ???

Asked by: BIGEZ
It sounds like you back fed the circuit from the existing fuel pump relay, I disconnected mine just by pulling the relay apart, the original fuel pump relay is fed from the starter relay and you need to get the power from your FCRM/black box. also did you hook up your inertia switch and did you tie the wires together in the trunk where the inertia switch use to be. Lastly if you did back feed the black box/FCRM check your fuses in the unit. Read my post and this may help you with how to wire up everything. NANotch
Answered by: NANotch
Date published: 2015-10-21
  • 2016-05-24T09:27CST
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