86 gt frying wire $5,000 later please help

You kinda lost me. That green wire looks like a real biggie though. I just can't figure out what you're talking about.

For your injectors, have you checked for 12 volts to one or more injectors (it will show constant key-on 12 volts)? If missing that, trace wiring, looking for a pinched feed wire if any of the top end was apart.

Good luck.

86gtriceeater said:

is the "bigger" fusible link that controls most everything..yes the top end was apart so i will certainly look but ive been looking for hours and hours man...also i used a noid tester for injector pulse and got nothing...should i still check for 12v at the injectors? is voltage the same as pulse? thanks man you guys know your shi*

Click to expand...

Yeah, testing for 12 volts at the injectors (just check whichever is easiest to access) is more specific than using the noid light. You will ground the negative lead of your meter to the engine and put the positive lead to the red injector wire. If you have 12 volts (with the key on), you can be reasonably sure that you're missing the ground pulse from the computer (to fire the injectors).


The injector circuit: the red wire is always hot with the key. It's the ground that is 'pulsed' (like a strobe light) to excite the injectors. Each injector has a wire from the computer going to it. So you could say that the positive wire to each injector is constant and the ground 'feed' is pulsed (recursively momentary).

Not sure if that makes sense. Jrichker is outstanding at explaining things - much better than I.

Good luck.

You have obviously shorted something in the main power circuit to ground. Find and fix the short
before you worry about not having an injector pulse. Once the short circuit is fixed, the other
problems will probably clear themselves.

Check out the diagrams and disconnect one thing at a time that draws electrical power off the
overheating circuit. When you disconnect the offending part, the wire will stop overheating.

Diagram courtesy of Tmoss & Stang&2birds


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website
host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif


Autozone wiring diagrams:
http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model cars
Computer/fuel pump/ignition wiring diagram, 86 model http://www.autozone.com/images/cds/gif/large/0900823d80167158.gif

86gtriceeater said:

...anyone have the 86 wiring diagram?http://img255.imageshack.us/img255/7051/picture017fh4.jpg

Click to expand...

I couldn't make out much in your last picture link.

Here is a diagram for an 86.

86gtriceeater said:

........... please inspire me with your brilliant genius!

Click to expand...

That's JRichker you're describing. I try to assist where I can (often simply while he is away).

For your AC, here's a diagram. Ensure you're looking at the correct engine size/section of the diagram. otherwise, the links JR provided can be of assistance.

If it was me (and I am an oddball), I would trace the problem wire from the solenoid as far as I could, looking for the location of the short. If you cannot trace far enough to find the issue, I would disconnect the tributaries that branch off that main line. Then plug each back in until you plug one in that starts to cause an issue (of course, have a fire extinguisher handy the entire time!).

Jrichker might have some more sterile methods for you - that's how a hack like me does it. If you have a short finder, that can be helpful too (I use one but most folks dont have one so I don't mention it).

Good luck.

Fix the overheating fuse link first. Do not attempt to run the car with the fuse link overheating.


Simple process: look at the diagram.

The blue fuse link only serves the computer and some relays that control auxiliary circuits.

The ignition has its own fuse link and the A/C draws power for the fan and compressor from a separate circuit.
It only uses the computer to turn the relay on and off.

The fuel pump has its own separate fuse link as well. It only uses the computer to turn the relay on and off.

The dark green fuse link only protects the alternator. Do not put any other devices on that fuse link! If you have
anything else wired to the dark green fuse link, disconnect it and wire it to the battery side of the starter solenoid.

Be sure that the dark green fuse link is on the same stud on the starter solenoid as the battery cable. The starter is the
only thing that goes on the other stud.

Disconnect the dark green fuse link at the solenoid and then try starting the car. If you get no heat from any of the
fuse links, the odds are that the alternator has failed or the black/orange wires have shorted to ground.
Most auto parts stores will test the alternator off the car for free.

Blue 20 gauge fuse link and green 14 gauge fuse link wire is available at most auto parts stores.

The orange wire is the ground for the O2 sensor heaters. The preferred spot to ground it is on the back of the cylinder head or one of the lower intake manifold bolts.

Your pictures are postage stamp size and ook like colored spaghetti. They are of little use in trying to sort out your problem.

AutoZone wiring diagrams

http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model Mustangs

make sure you have a good ground from the head to the body.....

The new pictures show that the wiring does not look like colored spaghetti, it looks like colored spa-ghetto.

First photo:
Every wire that connects to the starter solenoid needs a ring terminal crimped on it.
There is no way that wad of stripped wires wrapped around the stud makes constant good electrical contact.
The wires will shift and compress, making resistance, which makes heat, which makes more
resistance and more heat. Crimped or soldered on ring terminals will not compress or shift once the
nut is properly tightened on the stud.

Second photo:
The wire color and stripe are the key to what each wire does. The photo does not make accurate
identification of the stripe or even wire colors possible. You will need to write each wire color and
stripe down along with the size. On the diagram, LT is light and DK is dark. Do not omit that
important part of the wire color description when you write down the wire colors.

Wire size definitions: since the wires don't have a size imprinted on them, this may help. At this point
I am not confident that you can look at a wire and make a judgment as to what gauge it is.

Really big wire = 4 gauge battery cable.

Big wire = 10-12 gauge wire like the black/green wire that is the computer power ground

Medium size wire = 14-16 gauge wire like the red/green wire on the ignition coil.

Small wire = 18-20 gauge wire like the light green/pink wire on the ACT sensor

Use the diagram to find the wire color/stripe and identify what it connects to

86 Mustang 5.0 engine compartment wiring:.


If you lack the ability to read the diagram, or can’t find a connection for a wire, post the wire color/stripe.
I will attempt to help. However, this is only as good as your ability to accurately describe the wire
color/stripe and size. Green/red is not the same as dark green/red.

AutoZone wiring diagrams for 79-88 Mustangs are at http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp

Third photo:
The orange wire gets grounded to the back of the cylinder head, or to one of the lower intake manifold bolts.
Leaving it connected to the top of the intake manifold leaves a very bad impression of your workmanship and intelligence.

Wires that connect to ground or to studs MUST have a ring terminal on them to assure a solid, reliable connection.
Do not strip a wire and wrap it around a stud or bolt and expectit to work properly under heat and vibration.

Solder wires that need to be spliced together and cover the soldered joint with heat shrink.
Do not just twist wires together and tape them. This does not make a reliable connection.
See http://fordfuelinjection.com/?p=7 for help on how to do it the right way.

The 10 gauge black/lt green wire is the computer power ground.

I have given you the tools you need to do the job. The rest is up to you. The diagram has the wire colors and functions on it.
Make a table like this:

Trace out each wire you have and use the table to list them. Add as many lines to your table as you
have wires that are loose or you are not sure where they connect.

Use the diagrams!!!!


Additional wiring diagrams for an 86 Mustang are available at:
http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp

wow man...you got yourself in one hell of a mess...first thing i would do is go back and soder and heat shrink all the connections you have made...all that twisting together is what you do when hooking your cd player in your house...not your car...that's a disaster waiting to happen

The black/green wire is the computer power ground.

The black wire with no stripe is another ground for something else. Look at the diagram and take your pick

Jrichker's list/chart idea is the way to go and is how I handle this stuff too. Or I will draw a likeness of how the wires are oriented and label their colors. I then test each wire with my meter to try and determine what it might do. I write all this down because I'm slow and it takes all my mental power just to keep my testing methodology and meter settings straight, let alone what wires I've tested and how they tested. If you have wires of same or similar colors, put a piece of tape on them with an alpha-numeric (i.e. wire number 1) and label it as such on your chart so you know which black wire (for instance) you were testing.

This sort of plan of attack is what's needed. Anything else will burn circuits or just lead to plain luck (great until you find your parking lights work in concert with windshield wipers). Personally, it'd take me awhile to figure it out in person, let alone remotely. That's where your attention to note-taking and testing comes in. Be prepared for alternatives to wiring colors too (especially traces) since the wires discolor over time.

Good luck.