Fox T-Bird/Cougar Forums

Hello

  I have f***edup my ecc harness so bad its not funny(never use a 92 t-bird computer too many pins to change).  My car is an 86 elan t-bird built in 08/86.  I was wondering whats the difference between the 86 and 87 ecc harness and the computer?  I going to change the harness and computer this weekend. Do I need to drop my heater core for this job or will the harness slip by it?  What other harness can I use if I can't find one?  I need to get my bird on the road again so I can junk my caddy(pos)and get my bronco 2 on the road.

I need help fast.

Thanks in advance.

igiveup

There are alot of differences..  What year is your car?  If its in your signature I cant see it i have them turned off..

The interface where the engine harness connects to the fuel pump harness is different.  Where it connects to the dash harness is different.. and a few other connectors that are just different between the two..

Hello

  Its an 86 elan bird built in 08/86 with a 5.0.

igiveup

bump

I have an uncut 86 engine harness I can sell you.

Hello

I need to do this by this weekend.  My car is efi not cfi. I know 86-95 harness for the computer are quite similar.

igiveup

Yeah they are similar, but different... I'd consider the '91-'93 MN12 5.0 harness similar only, if you were referring to the wrap and dangling wires... Same for the '94-'95 Stangs... Those are major different... 

Listen to Claude, he's documented the differences in these harness'... Being it's a very late '86(almost too late, I'd have thought '86 production would have ended in July), it could share some of the '87 traits... I've never modded a '86, but there are definite differences in '87 & '88 harnesses...

What would be diferent between an '87 and '88 5.0 computer harness?

The two connectors by the booster mainly.. And the lack of a VSS signal wires in the 87.

Yeah The '87 harness actually has three plugs vs the '88s two...

I have a converted to mass air '87 harness in my TC... Maybe not the best choice, but it's what I had on hand...

Will the '87 harness be a direct swap into an '88?

Hello
 
  I don't think an 88 would work because of the body change. Or was that 89??

  igiveup

the 89 up harnesses are a  compared to the fox harness.  They are integrated into the farking headlight harness even.. Stupid design.  Forget them.. Plus there wasn't a 5.0 mn12 harness in 89 ;)

Get an 86 harness and it will plug right in.  An 87 or 88 harness will require equal amounts of work to fit in your car.  Another difference, the interface for the dash harness is about 12" further forward on a 86 harness than an 87-88 harness.....

Hello

  Well I went and got an 87 harness and computer from the junk yard.
The 87 harness has different plugins by the battery.  So what I did is rewired the orginal to what the colors are on the 87.  Car runs but missfires so im going to do a tune up and see what happens.

igiveup

Will the '87 and '88 be a direct swap with each other?

Hello

  Not too sure about that vinniebird.  What I would do is take a pic of yours and go and look at them.  All I know for sure is that the 86 harness is different.

  I had to disconnect my egr because it was surging.

igiveup

No

The reason I wanted to know,is,I have a second harness,and truthfully,now that I look back on it,I'm not sure if the car was an '87 or an '88.Those two years of cars looked identical.I pulled the harness for a fellow member who decided after I bought it,he didn't want it,so,I did the mass air conversion on it,and was planning on putting it in my '88.what was the difference betwen the '87 and '88 5.0 cars?

Connectors by the firewall.

What connectors by the firewall?More input.

The ones beside the booster.. a gray and a black one.. where the engine harness plugs into the dash harness..  the grays are the same between the two years.. but the black is different..  I believe Tom said something to the effect that he didn't even plug the black on in as all it did was run the gauges..

Well,I nmeed to run the gauges.I'll pull the harness out of the garage and check those plugs and then I'll HOPE they are the same.I may do that this evening if I can get off my butt.I hate working for a living.Leaves me tired sometimes.I need to just quit messing around and go ahead and win the lottery.

Checked the harness,the grey and black plugs are the same between the two harnesses.Cooooool (since I already did the Mass Air conversion on my extra harness).Now all I have to do is install it.

Hello
  Well I guess im going to take the harness apart and follow each wire back to each part.  What a pain in the A$$.  Ran the codes and 41, 33,  91 came up.  I know my car is running rich(not lean) and my egr is disconnected and my trany has no elctronics.  Dam Fords but I love my 5.0s.

Any ideas to help me out.

igiveup

86        engine      harness.........

$hit if you say so... I'm gettin' senile, I don't have a clue what circuits the black plug on the body harness connects... I had gages before I installed the aftermarket cluster, so that ain't it... Anyway, it's not connected and everything works... BUT you have to remember, a TC is quite different than the other models...

I believe it's at least partly for the turbo over boost and other related circuits... Possibly the speed sensor is in it as well... I tapped in at the harness where it comes through the floor at the shifter... My wires for S/S are run inside, under dash...

EDIT... Well we're both FOS, it's the gray plug that's not connected...

The Black plug by the MC fill is the one that's extra on the '87s... It feeds voltage to the EEC relay and ???? 

http://members.pen 15s.net/turbocoupe50/50wiring.jpg

this may help

If you search electrical tech,, i can assure you that you will find more wiring diagrams than you ever expected.

and the last page,,,

please dont say "my neck hurts":hick:  thats what they make

right click
save as

for.

hello

  Yes its the 86 harness.  Would a shot o2 sensor say its running lean?

igiveup

sorry to bring up a old post. But this kind of has some berring on my swap. Im using the 86 harness in my 84. And i do have power to the car and the headlights working just fine but i think i have everything wired up right but now when i go to try to crank the engine i get the click like its a dead bat, But the batt tests out fine. Now in thinking its my wires. also im not getting power to the fuel pump relay. But im asking where does the wire that comes off the silinoid where does that connect to on the 84 harness? and also if you jump the 2 pr0ngs on the silinoid shouldn't the starter crank? But what would help is if someone who did the swap could let me know what wires hook together and what not. And thanks for the help before hand if i forget to say so later.

cougar8775
im glad to see your back into a fox ,, you spent a long while without one thats for sure.

but i have to say it,,, wasnt this problem you have now similar to the the last problem you had with your old car?  ironic i think.

same car newer engine. But this has been a well kept secret for a while. But im just stumped plus there are a few extra wires i can't figure out where they go. studyed the diagrams and connected all the ones i saw and traced out but that brings me up to where i am at now. oh and thanks jcassity.

softtouch has the older evtm,, incase you have body harness wiring quesitions. 
other than that john, i wouldnt be able to give you anymore wiring info than what i have.

if all is well, then with your key on, and crossing the solenoid should result in the starter kicking in.  if it does not, back off and think about what you have wired.

also, make double sure your battery connections are good as well as your ground cable from the bat to frame and to engine block.

If the eec relay does not get power, a lot of stuff wont work that are relay controlled as well.

when you turn on your key, you should have power on one of the legs going to the eec relay.  check that first off.

Sup bro. I think I have both. 1..... Make sure your starter is hooked up right, all the wiring is connected. Remember my car did this when me and you and steve did it.
 
Fual pump... same thing to test, ground a wire to get it to work. If not run a hot wire like we did.

si its safe to say its ether my wire to the starter or ground? ive gone over my grounds even had to make a new one for the ground from the batt to chassie. but i know there is a red/lighr green wire on the body harness that gets power with key on but i have no clue what it controled or goes to. fuel pump relay maybe? any insire would help greatly since its getting ever closer to snowfall(cringes) and i do whant to drive her before then. also i don't whanna run a hot wire o it permanatly just to test it. i do want to do this right since it is a project that ive wanted to do for many yrs now.