86 EFI computer harness, power??

[v8only]

I'm not sure if this helps or not, but I went through my photo albums and found a couple of pics

In this pic, you can see where the fuel pump wire ends up under the seat, and the ebrake wire at the ebrake




and here is some underdash wiring. I'll be pulling my dash this weekend, and when I do, I'll take much better pics.

[paul78zephyr]

I'm not sure if this helps or not, but I went through my photo albums and found a couple of pics

In this pic, you can see where the fuel pump wire ends up under the seat, and the ebrake wire at the ebrake

Thats strange as the ebrake connector and the 2-pin gray connector shown near the FPR in your first (big) pic, I dont those connectors at all in Deans pic of his 'FPR harness'. These are both 86 harnesses?

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[v8only]

yes, that was a 100% unmolested harness from my 86 gt vert, carpet had never been out before that point

[Dean_T]

Okay,

Let me post this first and I'll answer in next post



Here is the Driver Side Harness and the Computer Harness thrown together in one shot. I kept the previous pictures (with updates) so everyone can see them apart and together.

Note I moved the HEGO harness to the right connector. Also note, the [IGNORE] Fuel Pump Relay [/IGNORE] Power Windows and Locks harness is mostly connected to the Driver Side Door Harness and the Passenger Side Door Harness. I need to track down where the power goes to the Driver Side Door Harness since the Pass. Side Door Harn. is slave to the DSD harness.

12/01/10 NOTE: 3-Pin connector in lower left of picture does not go to the tail light harness, it goes to the Fuel Pump Relay harness.



Here's the dash harness still attached to the dash. As you can see, I am missing the E-brake harness (whoops, no I'm not - it's part of the Tail Light Harness - Dean T), transmission wiring harness, and the console harness. The radio harness is hopelessly FUBARed.

Next is to rat out the wire codes of the important parts and where they go.

I'm very close. I can feel it.

Regards,

Dean T

[Dean_T]

Thats strange as the ebrake connector and the 2-pin gray connector shown near the FPR in your first (big) pic, I dont those connectors at all in Deans pic of his 'FPR harness'. These are both 86 harnesses?

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

Whoa, that is weird. The E-brake switch and seat belt connectors are attached to the Tail Light harness in the '86 Convertible I have - you can see 'em in the pictures on page 1.

Dean T

[v8only]

dean, which of the dash wires connect to the interior lighting (the rear view vert mirror light, and under dash lights....

also, which ones control the power door locks??

I lost those functions last time I pulled the dash

[Dean_T]

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.

Mark,

I think you're on the right track, all right. In my '84, I'm going to have the fun and joy of crossing over the '86 A/C Relay control wiring with the '84's A/C Clutch Power wire. Then I have to figure out which A/C Pressure switch harness to use. Fortunately, I know how the '86 A/C pressure Switch and Relay are wired up.

The coil, Self Test Connectors and the 4-pin and 8-pin connectors by the power Brake Booster is also going to be a joy to sort out.

Good Luck, Mark.

Dean T

[Dean_T]

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?

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

Yes, I believe that is correct, although I will have to verify if it pops out the firewall or goes through the door jamb area first. I really should have made notes of all these things before I ripped the wiring apart!


Yes, that is correct. You can see them in the picture of the whole kit-and-kaboodle-together.

[7/28/07 - Oh crud, I just reread Paul's first question and I misunderstood it. The Driver Side Door Harness I speak of is the harness that goes from the door to the doorjamb. This harness is for the door's power window, lock, and switches. The Main Harness under the dash going through the firewall on the driver's side I call the Driver Side Harness]


To answer a previous post, the individual harnesses I did on the ground but the shot with the whole enchilada I had to climb on a ladder to get the shot and had to wait until the patio was in all shade to get the best picture.

My head hurts now! Haha!

Dean T

[Dean_T]

dean, which of the dash wires connect to the interior lighting (the rear view vert mirror light, and under dash lights....

also, which ones control the power door locks??

I lost those functions last time I pulled the dash

Jeremy, I'll have to look at the mirror wiring harness (still in the car) to figure where they go. The power door locks, believe it or not, are part of the Fuel Pump Relay Harness. One big 8-pin connector goes to the drive side power door locks and switches, and the other connector is strung on the end of a long mass of wires (which is attached to the cowl just under the windshield) and pops out near the 8-pin grey connector for the Passenger side power door locks. I am very befuddled where the [(not the) Fuel pump relay Power Windows and Locks] get's it's power from but the inertia switch gets its feed from that long thin wire with the 3-pin connector that originated near the computer (goes across the firewall behind the dash and HVAC assy and pops out under the door jamb on the driver side then connects to the tail light harness.

Dean T

[Incognito]

Yes, I believe that is correct, although I will have to verify if it pops out the firewall or goes through the door jamb area first. I really should have made notes of all these things before I ripped the wiring apart!


Yes, that is correct. You can see them in the picture of the whole kit-and-kaboodle-together.

To answer a previous post, the individual harnesses I did on the ground but the shot with the whole enchilada I had to climb on a ladder to get the shot and had to wait until the patio was in all shade to get the best picture.

My head hurts now! Haha!

Dean T

Were the photographed harnesses from an automatic car? I am not seeing the 2 "clutch switch" pigtails. I thought these ran from the "headlight harness" or some call it the "underhood harness" that comes through the drivers side firewall.

[paul78zephyr]

Were the photographed harnesses from an automatic car? I am not seeing the 2 "clutch switch" pigtails. I thought these ran from the "headlight harness" or some call it the "underhood harness" that comes through the drivers side firewall.

They would be in the main underdash harness which is in that pic showing his dash. Its upsidedown on the floor so the clutch switch would be on the right side (drivers side) of the pic probably somewhere in or near that glob of connectors he labeled as 'steering column wiring'. If his car was an automatic the connectors are still there but would be taped up in the harness so they may be hard to see in his pic.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[v8only]

actually, unlike the 87+ harness, From another thread here I've learned that the auto harness is different, and has no taped up connectors for a 5 speed.

[Incognito]

actually, unlike the 87+ harness, From another thread here I've learned that the auto harness is different, and has no taped up connectors for a 5 speed.

That is sort of why I was asking about it possibly being different. My '85GT CFI/AOD does not have the clutch connectors. I have removed the dash, cluster, etc and cut all the tape and wrap out of the wiring harness under the dash. The clutch connectors are simply not there. I also chased the wires around per the wiring diagram.

I am converting this car to SEFI/T-5 and will have to work with this limitation.

Thanks,

Jonathan

[paul78zephyr]

actually, unlike the 87+ harness, From another thread here I've learned that the auto harness is different, and has no taped up connectors for a 5 speed.

I stand corrected. Thanks.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[v8only]

lol, one of our poor members here tore out his entire dash looking for those damn wires before coming to the conclusion that the aod's and t5 cars got a different harness.

[Incognito]

lol, one of our poor members here tore out his entire dash looking for those damn wires before coming to the conclusion that the aod's and t5 cars got a different harness.

If you are referring to me, I'm glad you found humor in your conclusion based on limited information. The whole interior is out of the car for a refresh and the dash was out for a heater core change anyway. As an addendum, misinformation has been posted often on this board that the clutch pigtails were "just taped up in the harness." Hopefully others will know better now. I'm glad you find things like things like this funny, keep it up.

Jonathan

[v8only]

If you are referring to me, I'm glad you found humor in your conclusion based on limited information. The whole interior is out of the car for a refresh and the dash was out for a heater core change anyway. As an addendum, misinformation has been posted often on this board that the clutch pigtails were "just taped up in the harness." Hopefully others will know better now. I'm glad you find things like things like this funny, keep it up.

Jonathan

lol, no it wasn't you... I had no idea you were even in the middle of a project like this....please don't assume.

I believe it was aaronatx, if memory serves, and this was about 4-5 months ago now. Should be a healthy thread on this.

[Incognito]

lol, no it wasn't you... I had no idea you were even in the middle of a project like this....please don't assume.

I believe it was aaronatx, if memory serves, and this was about 4-5 months ago now. Should be a healthy thread on this.

No problem at all, but from my recent post in the this thread (quoted below) I thought it may have been me...all is good.

That is sort of why I was asking about it possibly being different. My '85GT CFI/AOD does not have the clutch connectors. I have removed the dash, cluster, etc and cut all the tape and wrap out of the wiring harness under the dash. The clutch connectors are simply not there. I also chased the wires around per the wiring diagram.

I am converting this car to SEFI/T-5 and will have to work with this limitation.

Thanks,

Jonathan

[paul78zephyr]

one of our poor members here tore out his entire dash looking for those damn wires before coming to the conclusion that the aod's and t5 cars got a different harness.

Jeez, the poor bastard!

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[fordfreak300]

I am too tired to go work on my car right now. I got home from wok at 6am this morning slept for a few ours and have to be in bed by 4pm tomorrow to be back by 4am Monday. I just don't have the brain power to shift through the harness and keep figuring it out right now. My uncle also told me about the ac relay and needing to hook it up with the 86 wiring. I am putting my ac in but I wonder if I can make it work with out using the circuit in the 86 harness as the circuit in my 84 works just fine. Other wise I will have to figure out how to splice them in together somehow. Maybe I'll work on porting the one lower this weekend and use it to install.

[Dean_T]

Aw c@p, I just determined what I called the Fuel Pump Relay must be a relay for the power locks. The Fuel Pump Relay connector and harness is also in the Tail Light harness, just like V8only showed. I'll update with more pics.

Mark, if this works out, you won't have to think too much to get the wiring done - I hope.

What I was going to do for the AC Relay is to yank the wiring for the bugger from a donor car - everything from the computer to the power feeds. The solenoid part of the relay is controled by the computer. The switched part is simply spiced down between the AC Pressure Switch mounted on the accumulator mounted on the firewall and the power feed to the AC Clutch Switch. In my '84 I plan on leaving the stock headlight (Driverside wiring harness) and using the existing AC wiring but splicing in the relay as above.

More to follow...

Dean T

[fordfreak300]

how do you plan on splicing in the ac relay? simply splicing in off the existing power wire from the switch to the relay? Because that sounds like it may wok. I may get energetic enough to go pull off my carb and intake, set the #1 piston to tdc and pull the distributor, and remove the fuel pump today. I still need to get a fuel pump block off plate. Then again I still need to finish the other ported stock lower or install the one Jeremy gave me which needs cleaned up. I also have to move the solenoid to the other side of the car and lengthen all of those wires to connect. I also want to hide all of my wiring in the fender wells once the car actually starts and runs. Dang I a soo tired I am just rambling on.

[Dean_T]

Okay,

This is the Fuel Pump Relay attached to the Tail Light wiring Harness:



I didn't go back far enough on the E-brake light and seat belt switch harness to show the Fuel Pump Relay connector on the previous Tail Light Harness Pic.

I apologize for making this thread a mess.



Here is the T-5 wiring harness. Note the T-5 has a Neutral indicator Switch. Note the wiring color change in the back-up light harness. I haven't figured where that big 8-pin black connector goes into the dash exactly. The 8-pin black female connector on the Dash harness has wires with different colors than the 8-pin connector shown here.

Then there's that dorky 2-pin connector I don't know where it goes.



The console connects to the connectors in the middle of the dash area. You can see the connectors just above the hacked up radio harness in the previous dash picture. The console pictured here is a messed up '84 console so the wire colors don't match too well but the number of wires and connectors line up.

Hope this helps.

Dean T

[paul78zephyr]

I apologize for making this thread a mess.

Dean,
Dont apologize! You are the only one to fully document the 86 harnesses - with pictures and everything. Wiring harnesses, especicially those that are out of the car, can be very difficult and confusing to figure out. And Ford used the same connector housings in multiple places in some cases making it even more confusing. Dont knock yourself - the info you are providing is very worthwhile and needed.

Paul
1978 Mercury Zephyr - The FIRST FourEyed Fox

[Dean_T]

how do you plan on splicing in the ac relay? simply splicing in off the existing power wire from the switch to the relay? Because that sounds like it may wok. I may get energetic enough to go pull off my carb and intake, set the #1 piston to tdc and pull the distributor, and remove the fuel pump today. I still need to get a fuel pump block off plate. Then again I still need to finish the other ported stock lower or install the one Jeremy gave me which needs cleaned up. I also have to move the solenoid to the other side of the car and lengthen all of those wires to connect. I also want to hide all of my wiring in the fender wells once the car actually starts and runs. Dang I a soo tired I am just rambling on.

Mark,

The computer controls the solenoid inside the A/C relay so it's directly wired in - the input and output wiring of the solenoid needs to come from the '86 harness. Some where in the '84's harness between the '84's A/C pressure switch mounted on the accumulator and the wiring that goes to the a/c clutch, the switch inside the A/C relay needs to be spliced in.

The power that goes through the '84s A/C pressure switch then goes through the '86s A/C relay switch section (when the '86s computer energizes the A/C relay solenoid part) and out to the A/C Clutch connector to power up the compressor. The HVAC switch controls the power going through the A/C pressure switch and Relay switch but the computer can cut power to the A/C relay solenoid part thereby killing power to the AC compressor.

I think I need to type a little more clearly but am tired.

Dean T