My son in law took the ecm out of my 86 bird while I was at work.We are in the prosess of doing a engine swap.started to change over the 2.8's ecm to the 3.1's ecm and found out how big a mess it was and stayed with the 2.8 system.I told him to put the stuff back in and he left it pluged to the harness laying in the floor board.My problem is when I started to put stuff back in it's place,there is a female pigtail hanging in there not hooked up to anything.has a black wire 2 brown wires a red one and I think maybe some green.If ya need to know all the colors for sure i'll take it back apart.my fuel pump seams to not work,so was wondering if this might have anything to do with it,I think not.Might it have to do with a fog light conection? I looked at the wiring on all the 86 2.8 stuff and didn't see anything that looked like it.

 

Post a pic of the connectors in question

 

here are a few pics.I hope you can tell the wire colors.If not I will go back out and post them.I'll do it anyhow

 

VSS buffer box output connector

If you take down the gray trim piece just under the map pocket you should see it

 

what is a vss buffer box

 

Older ECMs are too dumb to decode raw VSS signals strait from the sensor so it goes to the buffer box which decodes it and splits it between the speedo, cruise and ECM. The ECM and speedo require a 4,000ppm signal while cruise requires 2,000ppm which the buffer also handles

Drop the trim piece and youll see a 4"x4" module on the far left or middle. They came in mostly yellow, but a few cars got cream colored buffers

 

looked into it.the vss buffer is silver or metal colored,and the wireing is alredy hooked up,I droped the ecm back out,there is no place to hook this up.It has 2 dark gray,1 green/black,1 pink/black and 1 black/white.I see nothing in the wireing diagrams that have that combo.Gry tend to stand for int.lights pink/blk thend to go to fuses,blk/wht are grnd.Is it possible this thing dosn't hook up to anything?This car still has the stock stereo so it would not be that.There was another conector back there closer to the center that was not hooked up to anything either.Only this one was square .Is it normal for there to be conectors that go nowhere,Or is it that people have unhooked stuff over the years.I don't see anything missing.It's like they are deadend roads.

 

I assure you its the buffer box connector. Heres the diagram
http://www.austinthirdgen.org/mkport...SS_V8_vinE.jpg

And a pic


Do a continuity test from the loose connector pin E to C207 (clear connector near the ECM) pin K. If they are continuous, then you need the buffer box in order for the speedo to work

 

I have a machanical speedomiter.That might be why no box in there.I bought this car as a roller.and having to get to know it as I put it back together.