O2 Harness

[Mustang5L5]

Test pin 30 to the blue/yellow at clutch pedal first. If you have continuity, then identity the other color wire on the same plug and and start tracing that back.

But yes, repairing the 1993 harness and reinstalling that so the entire car is 1993 wiring would be the best thing to do.

I want to say there were some changes in the 87-88 and 90-93 wiring that make some harnesses incompatible.


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[Black1987]

Test pin 30 to the blue/yellow at clutch pedal first. If you have continuity, then identity the other color wire on the same plug and and start tracing that back.

But yes, repairing the 1993 harness and reinstalling that so the entire car is 1993 wiring would be the best thing to do.

I want to say there were some changes in the 87-88 and 90-93 wiring that make some harnesses incompatible.


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Will do, but won't be tonight unless I sneak out with a flash light, working late

On a side note, what book is that

 

[Mustang5L5]

A mustang EVTM. They pop up on eBay from time to time, and are year specific. Probably the most used reference manual I have.

Getting one for a 1993 might be very helpful to you. One of these days, i'll get around to PDF'ing the whole thing and putting it online. It's a valueable resource


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[Black1987]

A mustang EVTM. They pop up on eBay from time to time, and are year specific. Probably the most used reference manual I have.

Getting one for a 1993 might be very helpful to you. One of these days, i'll get around to PDF'ing the whole thing and putting it online. It's a valueable resource


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So my wife snatched a pic for while she was lunch. It appears the gray plug that has the blue/yellow wire isn't connected to anything. The black plug beside it appears to be jumped to itself, red/blue wiring. My phone isn't loading pictures atm .

Hopefully that's wear the clutch switch is supposed to be, which brings up my next question. If I ground that plug and/or pin30 and car thinks I'm in neutral, can you drive the car that way?

 

[liljoe07]

So my wife snatched a pic for while she was lunch. It appears the gray plug that has the blue/yellow wire isn't connected to anything. The black plug beside it appears to be jumped to itself, red/blue wiring. My phone isn't loading pictures atm .

Hopefully that's wear the clutch switch is supposed to be, which brings up my next question. If I ground that plug and/or pin30 and car thinks I'm in neutral, can you drive the car that way?

Yeah, it wont hurt anything. Is there no clutch switch above the clutch pedal?

 

[Mustang5L5]

So my wife snatched a pic for while she was lunch. It appears the gray plug that has the blue/yellow wire isn't connected to anything. The black plug beside it appears to be jumped to itself, red/blue wiring. My phone isn't loading pictures atm .

Hopefully that's wear the clutch switch is supposed to be, which brings up my next question. If I ground that plug and/or pin30 and car thinks I'm in neutral, can you drive the car that way?

Was this car originally an AOD? What you are describing is typical wiring for an AOD car. the black plug is the starter circuit wiring and is jumpered out, and the grey wire is disconnected as it's not used in AOD wiring. That red/blue jumper is only found on the AOD cars.

Can you start the car without pressing the clutch in?

So both of these plugs should be connected to the clutch pedal switch. For now, you can stick a 5A blade fuse in the grey one which should complete the loop for pin 30. The car can be driven this way. It should also clear code 67 for you are one of the parallel loops is connected.

I also have a few suspicions here. Are you able to locate the black 8-pin connector in the driver's kick panel that matches the one I posted up above in post #74?

Is it 8 wires on both sides, or does the connector leading out to the transmission only have 6 wires like the plug on the left?


For now, stick a blade fuse in the grey plug, and then dump codes.

 

[Mustang5L5]

I'm guessing this is what you are seeing

I'm thinking you've got some AOD specific wiring going on here. I'd bet your trans harness also lacks the 2 wires that go to the NGS on top of the T5. You'd have a 6 wire harness in the driver's kick panel if that's the case. Up to you if you would like to replace this, or just jumper the grey plug under the dash and leave that in place

 

[Black1987]

Yeah, it wont hurt anything. Is there no clutch switch above the clutch pedal?

Appears not

Was this car originally an AOD? What you are describing is typical wiring for an AOD car. the black plug is the starter circuit wiring and is jumpered out, and the grey wire is disconnected as it's not used in AOD wiring. That red/blue jumper is only found on the AOD cars.

Can you start the car without pressing the clutch in?

So both of these plugs should be connected to the clutch pedal switch. For now, you can stick a 5A blade fuse in the grey one which should complete the loop for pin 30. The car can be driven this way. It should also clear code 67 for you are one of the parallel loops is connected.

I also have a few suspicions here. Are you able to locate the black 8-pin connector in the driver's kick panel that matches the one I posted up above in post #74?

Is it 8 wires on both sides, or does the connector leading out to the transmission only have 6 wires like the plug on the left?


For now, stick a blade fuse in the grey plug, and then dump codes.

I mentioned before I thought it was a 4 banger auto and the engine harness was changed,

Yes the car starts without the clutch, never thought to check if a switch was present just thought it got bypassed.

So you mentioned a blade fuse (in conjunction of grounding it) or just ground it out? My thought process is Pin 30 is not seeing a ground, so I need to ground that plug. So the red/blue still be jumped?

 

[Mustang5L5]

Must have missed that somehow. Can't beleive i didn't catch that given you were changing out an automatic O2 harness. I'd almost guarantee you don't have the correct trans harness either.

Not the end of the world. Stick a fuse in that plug and that should complete the NSS circuit and clear your code 67 and allow you to dump codes.

If you want to do it factory correct, you'll need to add a clutch switch, and add the correct harness under the car so the NSS on top of the T-5 can be connected.

 

[a91what]

The auto also has a NSS... why wouldn't it use the same circuit?

 

[liljoe07]

Appears not



I mentioned before I thought it was a 4 banger auto and the engine harness was changed,

Yes the car starts without the clutch, never thought to check if a switch was present just thought it got bypassed.

So you mentioned a blade fuse (in conjunction of grounding it) or just ground it out? My thought process is Pin 30 is not seeing a ground, so I need to ground that plug. So the red/blue still be jumped?

Red and blue stays jumped. You need to jump the blue/yellow to the other wire on the connector.

 

[liljoe07]

The auto also has a NSS... why wouldn't it use the same circuit?

It does, just in a different fashion.

 

[Black1987]

Must have missed that somehow. Can't beleive i didn't catch that given you were changing out an automatic O2 harness. I'd almost guarantee you don't have the correct trans harness either.

Not the end of the world. Stick a fuse in that plug and that should complete the NSS circuit and clear your code 67 and allow you to dump codes.

If you want to do it factory correct, you'll need to add a clutch switch, and add the correct harness under the car so the NSS on top of the T-5 can be connected.

Red and blue stays jumped. You need to jump the blue/yellow to the other wire on the connector.

I'm not worried about factory correctness just functionality.

I can put in fuse, this will jump it like @liljoe07 correct.

 

[liljoe07]

Yeah, but check that white wire for 12v when cranking the engine first.

 

[Black1987]

Yeah, but check that white wire for 12v when cranking the engine first.

I couldn't get a good read on the voltage, but I jumped the wire with a fuse.

Ran it around the block, ran a lot better. However, it fell on its face when I accelerated WOT. Threw a TPS code. Put a multimeter on it, .99volts.

Weird, actuated it through the to WOT and the voltage went to .02. Swapped it and maybe run around the block in a bit

 

[liljoe07]

What tps code number was it?

 

[Black1987]

63

 

[liljoe07]

Possible you have a bad spot in the TPS. You can do a sweep test with the volt meter hooked to it and see if the voltage drops out.

 

[Mustang5L5]

I believe 3.71 volts will signal WOT to the ecu.

Idle voltage should be anywhere within 0.6-1.1 volts. Don't go crazy chasing .99. Hook up dmm and open throttle with hand. Should climb somewhere into the 4.5-4.7 range. Exact numbers there don't matter, just verify voltage climbs and no dead spots.

Might be bad TPS here


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[Black1987]

To clarify, I did have a DMM on it and went from idle to WOT and it worked fine up until the pedal got close to floor, then it dropped down to 0.02.

Swapped with a spare and it goes from .98-3.80ish now.