Ok, is the O2 fuse link shown on this diagram? I see a blue 20GA blue link by the battery but we already talked about that one not being it.The fuse link for the O2 sensor heater is over by the passenger side hood hinge bracket from what I have been told. You will have to unwrap some of the plastic tape that covers up things to get to the fuse link.
The blue 20 gauge fuse link is for the ignition coil & ECC control relay.
Diagram courtesy of TMoss & Stang&2Birds
Your #1 & then #2 plan is right on target; stick with it.
It looks like the "Heated O2 Sensors Right & Left" are located at the bottom left of the diagram. I have a few questions for clarity sake:The fuse link for the O2 sensor heater is over by the passenger side hood hinge bracket from what I have been told. You will have to unwrap some of the plastic tape that covers up things to get to the fuse link.
The blue 20 gauge fuse link is for the ignition coil & ECC control relay.
Diagram courtesy of TMoss & Stang&2Birds
Your #1 & then #2 plan is right on target; stick with it.
Thank you for your patience and instruction. The best way I know to learn is to ask questions. I'll keep the thread updated with questions, observations, and results.The passenger side hood hinge location came from Ranchero50. I would put more trust in his advice because I know that he gave it from his personal, firsthand experience. On one other occasion I have had the diagrams be off by several inches concerning the location of the 22 KΩ resistor in the TFI feed to the tach and computer.
The arrow in your drawing is indeed pointing to the fuse link.
Diagrams courtesy of Tmoss & Stang&2birds
Ignition switch wiring - look closely and you will see the words HEGO and a gray/yellow wire on the ignition switch.
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.
94-95 Mustang wiring diagrams
http://www.veryuseful.com/mustang/tech/engine/#95-95Diagrams
Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.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
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
O2 sensor wiring harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangO2Harness.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
TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif
Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif
Mustang 5.0 Lights and Radio schematic, by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxLights-Radio_diag.gif
87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif
93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif
T5 Cutaway showing T5 internal parts
http://www.veryuseful.com/mustang/tech/engine/images/5_Speed_Cutaway_Illustrated.jpg
Visual comparison of the Ford Fuel Injectors, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/Ford_Injector_Guide.jpg
Convertible top motor wiring http://www.veryuseful.com/mustang/tech/engine/images/mustang88VertTopMotorCkt.gif
Engine mounted fuel injector harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangEngineHarness.gif
Location of the TPS, IAB, and the 10-pin connectors on a 5.0, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/TPS_IAB_Pic.jpg
Thank you! This is is getting difficult. I'll go down this list and see what I come up with.I would advise you to clear the codes and see if the code 96 goes away and doesn't come back. It is one of those codes that can get set if the inertia switch trips or you disconnected something in the fuel pump circuit while troubleshooting.
Google is your friend...
See http://www.the12volt.com/relays/relays.asp for more help...
A refresher on the code 96 is below...
Code 96 for 86-90 model 5.0 Mustang – KOEO- Fuel pump monitor circuit shows no power - Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits. The fuel pump lost power at some time while the ignition switch was in the run position. The main power feed to the pump is what is losing power.
Look for a failing fuel pump relay, bad connections or broken wiring. Check the fuel pump relay for damage and check the socket for corrosion, overheated wiring or loose connections. The fuel pump relay is located under the passenger seat. On Mass Air Conversions, the signal lead that tells the computer that the fuel pump has power may not have been wired correctly.
See http://www.stangnet.com/tech/maf/massairconversion.html
Look for power at the fuel pump - the fuel pump has a connector at the rear of the car with a pink/black wire and a black wire that goes to the fuel pump. The pink/black wire should be hot when the test connector is jumpered to the test position. . To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground.
86-90 Models:
Using the diagram, check the red/black wire from the fuel pump relay: you should see 12 volts or so. If not, check the inertia switch: on a hatch it is on the drivers side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. Good voltage there, then the fuel pump body to tank wiring harness connector is the likely culprit since it is getting power. No voltage there, check the Orange/Lt blue wire, it is the power feed to the fuel pump relay & has a fuse link in it. Good voltage there & at the Pink/black wire, swap the relay.
Keep in mind that the relay wiring and socket can also cause intermittent problems. Clean the relay socket with non-flammable brake parts cleaner or electrical contact cleaner. If you find damaged wiring at the relay socket, replacement pigtail socket assemblies are available at the auto parts stores. Be sure to solder the wires and cover the solder joints with heat shrink tubing if you replace the relay socket.
Re continuity test, do you mean: to unplug the PCM and unplug the fuel pump relay, and ohm test between the pin 19 terminal on the harness and the output wire of the fuel pump relay (which should be the two pink/black wires)?The 90 year model cars have some oddities about the wire colors. I would do a continuity test from the fuel pump relay to Pin 19 on the computer. You should see less than 1 ohm.
That is correct...Re continuity test, do you mean: to unplug the PCM and unplug the fuel pump relay, and ohm test between the pin 19 terminal on the harness and the output wire of the fuel pump relay (which should be the two pink/black wires)?
And this test should be done with the battery still disconnected from when I disconnect the PCM?That is correct...
Yes. that is correct.And this test should be done with the battery still disconnected from when I disconnect the PCM?
Ok, I did a continuity test between the FP relay harness (pink/blk wire), and pin #19 (different color wire than relay harness) and the meter buzzed indicating a complete circuit.The K ohm reading was .6-.7 for said wire. The test was done with battery unplugged, relay out, and ECM out, and red harness retainer out.The 90 year model cars have some oddities about the wire colors. I would do a continuity test from the fuel pump relay to Pin 19 on the computer. You should see less than 1 ohm.
According to the diagram that I posted, 4 wires is the correct number.Ok, I did a continuity test between the FP relay harness (pink/blk wire), and pin #19 (different color wire than relay harness) and the meter buzzed indicating a complete circuit.The K ohm reading was .6-.7 for said wire. The test was done with battery unplugged, relay out, and ECM out, and red harness retainer out.
To sum the scenario up: code 96, car will drive, wire continuity from relay pigtail to #19 confirmed, k ohm reading .6-.7, 12v at #19 koeo, 12v + at pin 19 koer, could not release ecm tab to remove #19, will R&R pigtail.
So that its clear what I'm dealing with and because ppl like pics:
Original harness w/butt connector on tan ground wire (loose connection). The wire also had exposed copper so I put some tape over it.
Back of original harness...
Laid out new next to old and labeled to match up wires...
So, I've got 4 wires coming out of the back of the harness/pigtail. Is that the correct amount?
Yes, thank you again! I'll have to drive the car for a bit to see if the code (i.e., 96) returns. Hopefully Monday I will return to diagnosing (with your excellent help), codes 41 & 91. I've already verified the O2 jumpers per your instructions and checked for 12v as well. They were jumpered correctly, but almost no voltage at the connector.According to the diagram that I posted, 4 wires is the correct number.
Power in = blue/orange
Power out =pink/black
Inertia Switch in = red/black
Computer provided switched ground = tan/lt green
No, not at this time.Yes, thank you again! I'll have to drive the car for a bit to see if the code (i.e., 96) returns. Hopefully Monday I will return to diagnosing (with your excellent help), codes 41 & 91. I've already verified the O2 jumpers per your instructions and checked for 12v as well. They were jumpered correctly, but almost no voltage at the connector.
Do you have any further input on code 96?
Here's apic of the spliced in harness. The connections were soldered and heat shrink was applied...
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