86 EFI computer harness, power??

[fordfreak300]

I am installing an 86 Computer harness onto my car for a carb to EFI swap. I got a great deal on it. I want to splice it into my existing wiring. Does anyone know what wires I splice off of the 86 harness to get power? I have a brown connector near the computer connector that has blk/or, or/blk, red/grn, red, and blk/grn wires coming out of it. Where do I run these wires too. Also is their any other wires I need to splice into power somewhere else that I havn't figured out yet? I would like to get started on this tonight or tomorrow.

[fordfreak300]

Does the connector by the computer connector just get a relay plugged into it? I have part of this figured out I think but not all of it. On the connector by the computer connector there is a wire that runs all the way to the front of the car to provide power from their for it, This is why I am assuming it is a relay. Can anyone with an 86 verify this? i know the red/white and green/yellow wires goto my MSD box under my seat, which is where I hid it. The power wier for my fuel pump also runs all the way to the front of the car so I won;t have to splice it there either, just hook it up.

I believe rd/light blue is crank only and will hook to the white/pink wire in my column.

The netrual saftey switch wires will be easy, I already have a functional neutral saftey switch so I will just connect the 2 new wires together and use my old one.

I need to check to see if I have a white purple wire which also connects to the 12v crank only.

[fordfreak300]

Ok here is where I am at now. On my 86 harness I have 2 connectors up by the booster. I am finding some of the wires on each connector. Now I have a white with purple on both connectors, should I connect them both together then to the steering column?

[Dean_T]

Mark,

I'll track down the '86 harness I grabbed from the wrecked '86 I have. The brown connector next to the computer I'm sure is the EEC Power Relay connector. Unfortunately, the '86 harness doesn't have the green connector near the computer like the later Mass air cars. That green connector was where the Run power and hot when starting wires go plus a few others. The Ford main harness instruction that Summit has in pdf doesn't seem quite as helpful after all.

I could swear the fuel pump relay harness is a separate harness from the rest of the wiring and so is the neutral start switch, clutch pedal switch, and back up light switch harness.

When I find them, I'll snap some pics of the connectors.

I'll dig into this a bit more. I plan on using the '86 harness on the '84 notch Mustang.

Dean T

[fordfreak300]

I am going to use my back up light switch harness,clutch harness and neutral safety switch harness. I am almost positive I have most of the power wires figured out. It is way easier than the newer harnesses as the fuel pump and that EEC relay have power wires that run to the front of the car for power. I am going to go over the 86 wiring diagram again and trace out the o2 harness but I think the power comes from with in the harness it's self. I will hopefully get started on this tomorrow. I have the day off of work unfortunately. But it gets me an earlier start than I had previously planned. I will post up anything I find so you will know as well.

[Dean_T]

Cool. I plan on looking for the '86 harness after work tomorrow. The '86 harness are a lot more different than I thought!

Dean T

[fordfreak300]

Yes I am finding they are way different, yet easier once you start mapping it out. I will try to take some pics and document what I am doing for others and for you dean so it will make it easier with the 86 harness. I just can't seem to find any real info from anyone who has done it unless they rewired the whole car.

so far I have the black/orange wire that is always powered on goes to the solenoid up front, as does the yellow wire for power to the fuel pump and fuel pump relay. So those are not spliced in merely bolted on. I cut the coil wires out of the engine harness side as I am not going to use the engine harness only the efi, fuel injection, and o2 sensor harnesses. I also will reuse my MSD 6 box so the red/grn wire will goto my box instead of the positive side of the coil, and the green/yellow which normally runs to the negative side of the coil will goto my MSD box. I already have the wire from my MSD box there so I will just put those onto the EFI coil connector and plug it in. I need to research what else needs power. I will do that tomorrow and post up my findings.

[paul78zephyr]

Ok here is where I am at now. On my 86 harness I have 2 connectors up by the booster. I am finding some of the wires on each connector. Now I have a white with purple on both connectors, should I connect them both together then to the steering column?

So is this a continuation of this thread?:
http://vb.foureyedpride.com/showthread.php?t=46157

At that thread you said you had two round black connectors with 4 wires each but I cant figure out if you said they were on your EFI harness or from the underdash harness that is in your car. Are these the connectors (near the booster) you are talking about?

Also the brown connector near the EEC is definately the EEC power relay connector.


Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[v8only]

paul, it is and it isn't.

he found out 100% for sure that the existing harness in his car IS an 84 harness., so what he is doing is splicing an 86 computer harness into his 84 harness.

[fordfreak300]

Paul, V8only said it correctly. I picked up a complete 86 harness and am only using the computer, injection and o2 harnesses. I am splicing those in. The 2 connectors I am referring too are on the 86 EFI harness. I just need to know what all needs power at the 2 round connectors on the 86 EFI harness near the booster.

I bought the EEC relay today so I can plug that in. I am hoping to get started this evening.

[paul78zephyr]

Paul, V8only said it correctly. I picked up a complete 86 harness and am only using the computer, injection and o2 harnesses. I am splicing those in. The 2 connectors I am referring too are on the 86 EFI harness. I just need to know what all needs power at the 2 round connectors on the 86 EFI harness near the booster.

I bought the EEC relay today so I can plug that in. I am hoping to get started this evening.

OK,
Sounds like a plan. Let me know the color codes on the wires on those two connectors. Im ptetty certain that many (not all) of the wire color codes are same for 86 as on 87-90 and I have fairly good documentation on those.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[Dean_T]

Okay,

I managed to find my '86 harness and now see where the '86 harness differs from the FRPP (was Ford Motorsport/SVO) main harness.

This is the '86 computer harness and where there is blue tape, I haven't a clue yet where they go.



[IGNORE THIS]Note the fuel pump relay harness by itself. I couldn't find where it connects. I think it connects to the tail light wiring harness but I haven't determine how the fuel pump relay gets power. I'll need to stare at it some more.[/IGNORE] The relay and wire harness is part of the power window wiring (update 12/01/10)

The following is the harness coming from the driver side of the car:



I have a hunch one or two of the three connectors near where the power brake booster would have been was for the windshield wiper motor. The other one may be for the under hood light. Unfortunately, I didn't have the wiper motor or under hood light readily available to verify.

Mark, in your conversion, make sure you use the starter solenoid the '86 Mustang uses - I believe the SEFI cars used a different starter solenoid than our carb cars.


The following is the wiring harness FRPP used to sell.



I noticed it's quite a bit different in some ways in that the fuel pump relay is integrated into the harness and is near the AC relay. The coil connector is also integrated into this harness, unlike the previous '86 Mustang driver side harness - which also has the connector to the AC harness. The FRPP computer harness has the AC harness connector. Note the green connector by the computer and the brown connector on the left - both connectors not present on the '86 Mustang computer harness.

Somewhere, I'll need to see where the transmission harness interfaces and which dash connectors differs from the '84 Mustang.

Fun-fun-fun.

Dean T

[fordfreak300]

Yes I still have a lot to figure out I think. I am off to work in a few hours and won't be home until this weekend. I'll post up the wire colors when I get home.


Dean, in the pic with the 86 computer and harness, you have the furl pump relay but not the connections for the fuel pump or sending unit. On mine the fuel pump relay goes into the tail light harness and has a connector that plugs into that connector in the center with the long skinny wires. The plug on the top left with blue tap is one of the connecotrs I am refering too. It has one of the wires that goes to the coil. The one next to it that is plugged into another short loom I have no idea what you have plugged in there. Both of those connectors plugged into the 86 engine harness I have.

Maybe you can post up the wire colors for each plug and Paul can sort it out for us.

I can't take any pics right now as my harness is laying in my car. I started installing it tonight while I did my heater core. I am hoping this next weekend to wire everything up and have all the hard parts mounted and fire the car up. The first order of business will be to make my mass air harness. That shouldn't take me long though.

[v8only]

you should be able to do it with a simple connector from a junkyard car off the mass air meter, and lengthening the wires to the dash....

I've got full install instructions for the conversion, including which wires to splice, and which to relocate on the computer pin block, if you want me to scan it... just let me know

[fordfreak300]

I already have it printed off, bought the wires, have the mass air connectoer to lengthen the wires on, and the pins to install onto the computer connector. Thanx for offering though. FYI for anyone reading this thread, I spent more in wire than if I had just bought the stupid conversion on e-bay.

[paul78zephyr]

Paul can sort it out for us.

Wow thats alot of harnesses, you have me scratching my head. Like I said the 86 is the one setup I have very little experience with.

Dean,
Remind me again what car you are putting this in?

In your first pic with the EFI harness the connector at top right with blue tape should go to the O2 harness. The black round connector with blue tape on the left in that pic I believe goes to the black round connector on the drivers side harness in the other pic (near the bracket for that tan box, and what is that box?) - if it mates be sure the wire colors match up. Most or all those grey connectors on that drivers side harness would connect to the main underdash harness on an 86 (up under the steering column). That long skinny wire coming off the EFI harness to a small gray connector (with blue tape) I cant tell - youd need to look at color codes. Does it look like it mates with anything on that fuel pump relay harness? If not it probably went to the underdash harness too. Its possible that FPR harness probably has alot of wires in it that have nothing to do with the FPR, you will need to look at that. Sometimes trying to use these harnesses 'piecemeal' is much more difficult as they contain wiring and connectors that you dont need but figuring out what you need and what you do not can be difficult. Obviously the piece you are missing is the underdash harness that would connect all these other harnesses together. Im sure you can use what you have though. You could just use the FRPP harness you have - its probably as much work - perhaps less - as trying to use the 86 harnesses.

Guys, without being there to pour over those harnesses with some schematics its really hard for me to see where it all needs to go.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[Dean_T]

Paul,

Understood. But for me, you have more intuition and common sense than I do.

So, I did some more snooping and determined that none of the connectors attach to the under dash harness so far. Oh, some connectors did fit but the wire colors didn't match.

So, here's what I've found out so far:



[IGNORE THIS] There is an 8-pin round connector near the TAB, TAD, and EGR solenoids with only has 5 wires attached. Wire colors are noted. This is one of the mystery connectors with blue tape[/GNORE] This wire goes to the HEGO. The connector the HEGO (Oxygen Sensor Harness) is plugged into by mistake is an 8-pin, 7-wire connector which match the same connector on the Driver Side Harness near the Power Booster - see post dated 7/26/07

I found a 4-pin round connector near the oxygen sensor harness connectors (just before the whole computer harness terminates at the A/C relay and negative battery terminal connectors). This 4-pin connector connects to a 4-pin connector on the driver side harness near where the power brake booster would be - all color wires match.



On the driver side harness near the power brake booster would be there is also a grey connector which goes to the wiper motor, and an 8-pin round connector which only has 7 wires attached. All color codes are noted.



And for reference, the FRPP harness. The color code for each can be found in the link to the wire harness installation guide which Summit seems to have.

Note, I've laid out the harnesses as close as possible to how they would be in a Mustang.

The '86 harness I intend to graft into the '84 Mustang - which is why I am closely following what Mark is doing. The FRPP would probably go into the '78 Friggin' Futura but may wind up in the '83 2-dr sedan first.

Odd, in all my fumblings, I haven't noticed the Self Test Input connectors on the '86 Harness as well as the SPOUT -both which I swear I saw on Mark's '86 harness. I also forgot to identify the MAP sensor on the '86 harness. It's near where the "salt and pepper" connector wiring leave the main harness.

I need to find the transmission harness and see if I can get a pic of the tail light harness still installed on the wrecked '86 Mustang.

Thanks all for the info, more to follow!

Dean T

(corrected some errors)

[v8only]

DAmn Dean, that's impressive. This thread needs to go right into the archives.

If I must stray though, what program did you use to type the text over the pic?

[fordguy]

on deans pic of the 86. the one marked unknown 3 pin goes over the top of the dash and down to the drivers kick panel, i think it is the fuel pump power supply.

[paul78zephyr]

Dean,
This is the best documentaion of 86 harnesses Ive seen anywhere! EXCELLENT JOB BROTHER!!

You said this came from a wrecked 86 you have? If so do you still have the 86s underdash harness? I think that would have the connectors that go the some of the 'unknown' connectors on those harnesses.

I guess I was wrong about the O2 harness - I had no idea that on an 86 EFI harness the O2 harness connects on the drivers side. You will have to dig into those wire color codes to the 'unknown' 8 pin connector on the passenger side and trace them in the harness to where they go. But I was correct about that connector near the booster going to one on the drivers side harness - except there are actually two on that drivers side harness (near the tan box bracket) and I thought it was the larger one but its the small one. The unknown three pin connector 'big yellow' wire has to be power, but from - or to - what? You need to try to trace the wires from the unknown connector in the harness. May be a little difficult without stripping off the loom but dont do that unless you really need to. The loom and tape fall apart once its off.

Sorry I have not shed more light but this is all pretty much the first time Ive really seen a 86 harness set laid out like this. Ill keep digging from anything I have.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[Dean_T]

Okay, Some more interesting stuff:

I understand what Mark was saying now. The Fuel pump relay harness plugs into the driverside door harness big time and one connector plugs into the tail light harness. [7/28/07 - This is not what Mark meant - I mistaken the Power Window and Lock harness as the FPR harness - the Power Windows and Locks Harness plugs into the Driver Side Door Harness and the Passenger Side Door Harness]



There are three connectors left on the [IGNORE]fuel pump relay[/IGNORE]Power Windows and Locks harness I do not know where they go yet. The big grey 8-pin connector I'm holding, the single male bullet connector, and the 2-pin connector with one PNK/WHT (?) layin on top of the [color=red][IGNORE]fuel pump[/IGNORE] (power window) relay. The wire color is hard to tell - the color is all run together. I have a hunch the connector in my hand goes to the dash harness and the bullet connector goes to the female bullet connector in the computer harness. I do have the dash harness, it's still installed in the '86 Mustang's dash. I'll have to get pics of it and the fuel pump relay connector next.



Remember the 3-pin mystery wire on the computer harness? I got the color wrong and corrected it in the previous picture and it hooks up to a connector in the tail light harness. Mark mentioned this previously.

12/01/10 update See Post #19 by Fordguy. He is correct, this connector plugs into the wire harness to the fuel pump relay. Note the wire colors and scroll down to the pics of the fuel pump relay harness.

Oh, BTW, the two connectors in the blue roll of tape in the previous picture are from the tail light harness.

There are a ton of connector here and I'm sure most go to the dash harness and some probably connect to the multi-function turn signal switch and some of the single wire connectors may go to the seat belt wire.

I haven't found the transmission wiring so I can't compare it to the dash harness connectors and someone stole the console from the wrecked '86 so I don't have a clue what those connectors look like unless the '84 console has the same wiring. I can grab the '84's console next and find out.

Jeremy, the program I used to insert the text came with my old digital camera I'm using. It's not the best (I can't draw lines) but it does okay.

RUH-ROH! I screwed up. Apologies to Paul. I put the HEGO (Oxygen sensor) harness on the wrong connector. The HEGO harness goes on the 8-pin with 5 wire mystery connector on the computer harness (near the TAB, TAD and EGR Control Solenoids).

That 8-pin connector I had the HEGO sensor hooked into? That goes to the 8-pin 7 wire connector on the driverside harness near the power booster.

Oh, and the spout connector is next to the TFI connector. Also, the '86 has one Self Test input connector.

Yup, I goofed. I'll have to reshoot those two pictures...

Thanks all for the input, it helps in the searching. I guess I should start figuring out what each of the wires are and where they go...

Dean T

[v8only]

I have to fix some dash wiring soon....Not sure how far you plan on going once you tear out that dash harness, however my power windows and interior lights are non op after a dash pull from a couple of years ago.

once you get that dash harness out, any known connectors that you know of, please label and post up. I'll help too with the connectors that I know of, and we'll have basically a complete 86 harness documented here.

Hopefully I can get my lightening and power accessories fixed soon

[fordfreak300]

Dean, where our installs will differ is with the whole coil deal. I am using my MSD ignition and cut the connector for it off. I should have left it on and used the otehr side of the connector. Ohh well I'll stay MSD forever anyway. I am glad you have figured out all that you have so far and I am glad to have helped. I will be working on my car a little this weekend. I have a few family things that came up such as mky sister just moved back to town after 4 years so I have to visit with her. If I doin't fire the car up this weekend I will trhe next weekend for sure. I have a sneaky feeling getting power for the EFI harness is going to be easy. I think the only splicing I will have to do is for my MSD box to be installed, and I think I will remove the FUel related wiring out of the tail light loom and wire it up that way. It will be easier for me that way, to remove any unneeded wiring as to not add any extra weight not needed. I want to keep the weight down on my car as much as possible still. I am going to weigh it aftrer I comlete this and see how much extra weight I gained from the conversion.

[paul78zephyr]

BTW Dean,
How did you take those pics of the harnesses? Did you stand on a ladder or something? I want to take pictures of my modified 90 harness the same way.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[paul78zephyr]

Okay, Some more interesting stuff:

I understand what Mark was saying now. The Fuel pump relay harness plugs into the driverside door harness big time and one connector plugs into the tail light harness.

When you say 'drivers side door harness' do you mean the connectors on the main underdash harness that come out on the drivers side kick panel area near the door?

RUH-ROH! I screwed up. Apologies to Paul. I put the HEGO (Oxygen sensor) harness on the wrong connector. The HEGO harness goes on the 8-pin with 5 wire mystery connector on the computer harness (near the TAB, TAD and EGR Control Solenoids).

That 8-pin connector I had the HEGO sensor hooked into? That goes to the 8-pin 7 wire connector on the driverside harness near the power booster.

Glad you caught that by double checking the color codes. Many of the harness connectors use the same connector housings.

So the 4-pin and 8-pin connectors on the EFI harness connect to the 4 pin and 8 pin connectors on the drivers side underhood harness near the booster, correct?

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox