Hoping someone can take a look at their 86-88 EFI 5.0 engine wiring harness and help me out. I was working on the driver's side around the starter solenoid where the engine harness meets the chassis harness. This is the harness I have an issue with:
From the above picture/post, you follow that harness down to where all of the connections are made. I have mine all separated out at the moment:
Then, I get to my "issue". One of the connectors (black, round with a flat side, 4 pin) has four wires coming out of it. The black wire coming out of this connector goes nowhere ... and it actually looks like somewhat of a clean cut. I haven't been able to diagnose where this goes. I haven't found a corresponding black wire in the main part of the harness. I'm hoping someone can check their harness and let me know where this is supposed to go.
What are the other colors to that connector? Looks like the plug to the o2 harness to me.
The colors are solid black (broken), green w/ yellow stripe, blue w/ red stripe, and gray w/ yellow stripe.
Cant tell for sure by wire colors, but I think its the evp connector that goes to the egr.
The connector itself connects to the chassis harness in that big hodge podge around the starter solenoid and ignition coil on the driver's side just behind the battery, that isn't really my issue. The connectors/connections themselves are all good. I was just poking around and found this loose wire. I guess what I'm trying to find out is where this wire should go? Does the wire run out of this connector and to another one or does it just run through the engine harness to the computer? If so, I didn't locate the other end of it.
Black wires are grounds, you sometimes find a loose end that is in harness but doesn't connect to anything as some feature isn't there or was deleted...
Out of 60 wires ran to the computer, maybe 20 actually hook into anything.
At it's newest, you are messing with a 29 year old car. Every time I see smog stuff hooked up, it amazes me.
Thanks guys. I assumed it was a ground being a solid black wire and figured that I'm relatively "ok" since I didn't have any issues prior to finding it (that I'm aware of). Just curious as to where it goes if it indeed goes anywhere. I'll have to snoop around the next time I'm in the junk yard to see if I find anything different.
Is there a corresponding wire in the plug that connects to it and if so would it be easy to chase out? If you find it going to something then it may clue you in to whether or not it needs to be connected on the other side or if it was for a differently optioned car.
what year harness is that?
they like to change wire colors between 86 and 88
Is it a mustang harness?
Yes, there is. I'll post a pic of the corresponding plug below. The "broken" black wire on the male connector goes to the black wire with the white stripe in the female connector shown in the pic.
So ... things get a little "interesting" in this regard. My car is an 85 and has all of the original chassis wiring (headlights, dash, interior body back to the taillights) ... BUT ... the engine harnesses (small harness on the actual engine that goes to the injectors and a lot of the sensors, plus the main engine harness that this smaller harness plugs into and then goes to the computer) is out of an 86 5.0 EFI Cougar. I specifically searched for one of these harnesses in salvage yards because it is a direct plug and play into the chassis harness when converting from a TBI 3.8 V6 to an EFI 5.0 V8. The only wiring modification I had to make was the addition of the mass air. The 87/88 Tbirb/Cougar engine harness as well as the Mustang harness are very similar, but they would not have been a direct plug and play with the chassis harness.
This is real long shot here. Early Ford wiring used blue with a red tracer for 12v lighting in the radio and dash lighting. Looking at that harness is it possible that it is for a trailer connector with the blue wire used as a feed to control a lighting relay? Like I said, this is a long shot but I'd try ringing it out with the lights,signals,and key on just to satisfy my curiosity.
From the 85 EVTM:
The 4 pin connector for the 3.8L V6 idle speed control motor wires are:
BK/W (signal return for the EEC sensors)
Y/BK
W/LB
LG/W
Does this match your "female" connector?
He said the connector was on the 86 ecu harness... i have one in the shop, and there is no connector like that on mine... I couldn't even find those wires on the harness and
Hoping a few more pictures may help to clarify. The engine computer harness leading from the computer, through the firewall, runs across the length of the firewall from the passenger side of the car to the driver's side. This particular harness is out of a 1986 Cougar EFI 5.0 car, I think this harness was a one off for this year and was then slightly modified for the 87/88 cars.
As you follow the harness to the driver's side, it terminates at several different connectors that mate to the chassis harness behind the black plastic cover around the stater solenoid and ignition coil. In my photos, I have the wires exposed and pulled out of the loom due to trying to find where the loose black wire goes. The connector in question has a red arrow on it in the last pic.
I dont have that connector on any of my harnesses
So ... the plot thickens ... thanks for taking a look!
Well, I was able to answer my own question to some degree. Managed to find another '86 5.0L EFI Cougar that was relatively new to a somewhat "local" UPull It yard. So ... I pulled myself a spare engine harness ... and ... it has the exact same connector with a black wire that goes nowhere.
was it plugged into anything? or does it look like it was?
It was plugged into the corresponding 4 pin connector, but that particular wire did not lead anywhere. It doesn't appear that it ever did either. It looks just like mine ... same length and a clean cut/termination like someone just cut it with a pair of cutters. I decided to just shrink wrap the end of mine and then tape it to the other wires running to that connector ... just odd as there is a wire in the corresponding connector and you'd figured they wouldn't bother putting a wire in if it wasn't going to lead to anything.