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Discussion Starter #1
Trying to fix my airbag system. Originally had a code for blown thermal fuse in the diagnostic monitor. I have replaced the fuse with the exact specification thermal fuse. Once plugged back in I now have a code 13. I unplugged the blue box diagnostic monitor before it could blow the thermal fuse again. We removed the clock spring and checked all connectors for proper readings and shorts to ground. All measurements of the testing were fine, no faults found. We followed the ford diagnostic flow chart. I am aware of an airbag reset connector on 1994 and newer stangs but from what I can gather there is no reset connector for the 93 (or earlier).
I'd really like to get the system working again. I tried another blue diagnostic module but it too blew its thermal fuse when plugged in.
I am showing no shorts to ground or any other reason this code keeps coming up.

All testing was performed with a 2 ohm simulator plugged in instead of the airbag. (I gathered that 1993 used a 2 ohm simulator and earlier cars used a 1 ohm).
We have many hours into this diagnostic and would really like to finish this up (and no, I don't want to just pull the bulb or put black tape over it)

I found a lot of information on a website called very useful stuff with airbag schematic diagrams and a list of error codes. only problem is the info is for 1992 mustang or 1994 1995 skips over 1993.

I really need a 1993 airbag system wiring schematic (can't find one anywhere).

can someone please help me. thanks
 

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if you blow a fuse

there is a short to power or ground, there is NO load

you have not found it.

are you saying a 93 is different then a 92?
 

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code 13 is a short to ground, no?

in the air bag circuit

that is two wires
 

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Discussion Starter #4
Not sure if 92 is different from 93. I was told 93 uses a 2 ohm resistor and that the clock spring is different from a 92. Not sure about the no load statement. all checking was done with a multimeter and the airbag diagnostic monitor unplugged. Once plugged in I can turn the key on and leave it on long enough to see the code flash and then quickly unplug the diagnostic monitor before it blows its fuse. Not sure how everything seems to be checking out and yet that code 13 remains followed by blowing the thermal fuse if the key is left on for too long. Very perplexed. I would love to see a electrical diagram for a 93 to see if there are differences compared to the 92 system.
 

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there is a short to ground on the air bag circuit

there are two wires that come from the module and go to the airbag through the clock spring

the short can be anywhere along those two wires

what readings are you getting with the multimeter, as you say it checks out

that is determined by what tests you have done

the load statement is just that

every circuit MUST have a load

the load is the airbag and the resistors in parallel

if current by passes the LOAD, that is a short.
 

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Discussion Starter #6
The following is the procedure we used for checking.

1. Disconnected the air bag diagnostic monitor and replaced the air bag with the proper test resistor.
2. At the black monitor connectors checked the following:
a. Checked pin 11 (CKT 614, clockspring winding circuit) resistance to ground). Showed open circuit.
b. Checked pin 10 (CKT 615, clockspring winding circuit) resistance to ground). Showed open circuit.
c. Checked pin 10 to pin 11. Read about 2 to 3 ohms (the resistance of the test resistor.
This should indicate that the air bag circuit is not shorted to ground.
3. Removed the test resistor. Pin 10 to pin 11 then read open circuit because no test resistor. This should indicate that the circuit conductors are not shorted together.

Also tested with clockspring disconnected and showed no short to ground and no short between circuit wires.

Also tested the front sensor circuits in the same way. Read no short to ground. Read 1,180 ohms across each sensor at the monitor connectors

Sorry, should of had this info in the earlier post. Thank you
 

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that procedure is flawed

ohm tests to ground depend on your meter

if you blow a fuse, there is overcurrent, you have to understand there is a short

i suggest you remove the air bag, put your test resistor back in

disconnect the plug at module the probe the circuit and wiggle the wires and clock spring

what is the amp rating of the fuse that blows?
 

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Discussion Starter #8
Just to clarify, the fuse that blows is the thermal fuse located within the airbag control monitor (the blue box). We are able to unplug it fast enough after code 13 is reported to keep the thermal fuse from blowing each time. Our checking confirmed there are no short circuits so not sure why this code is present.
 

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when you have short the monitor sees voltage going to zero

the fuse blowing confirms that

the fuse, the monitor, and me, are telling you have a short

you saying NO, you have no short

you have not told me the actual voltages you got from testing, forget ohm test, useless

i told you how to test, but you refuse, so i leave you be.
 

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Discussion Starter #10
According to ford repair manual we should be checking ohm resistance not voltage. Do you know if the 1993 Mustang has an airbag code clearing connector? I know the earlier years used 2 blue boxes (one for battery backup and one for diagnostic monitor). The 1994 and later has a seperate connector near the glovebox to clear the codes.
 

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i am going to give you a tip

all monitoring circuits are voltage or current

not resistance

I can understand how it monitors by the diagram

the ford manual, and all manuf for that matter, have you do resis tests

which is INCORRECT, if you don't believe me that is fine

it has been proven over and over again, manuf flow charts are for the most part, useless

I work in controls a lot, so this info I give you is not a guess
 

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Discussion Starter #12
Update on airbag light issue. It turns out the airbag monitor (blue box) was faulty and was causing a code 13 to display. Once all circuits and sensors were verified to be in perfect working order we installed a used airbag monitor and the issue is fixed. There are no codes in the system and the light is now off. I bought a couple of used monitors and they are also in fine working condition (i will be keeping them as spares). So for anyone going through what we did be aware that the code or codes being flashed by the airbag light may not really indicate a problem if after thorough checking the rest of your system checks ok. The airbag monitor is hard to find in new condition as Ford has it listed as obsolete. My dad put together a list of cars that contain the same airbag monitor as my 1993 Mustang (should be the same one you need for all 1993 Mustang but not definite on that. The part number you are looking for is F2AF-14B056 AD. The following list are vehicles that contain that part number monitor (double check after removing from the donor car to make sure the part number is correct.


AIR BAG DIAGNOSTIC MODULE
F2AF-14B056 AD




AIR BAG, (LH STEERING COLUMN) 1994 Ford Aerostar


AIR BAG, (BEHIND RADIO) 1994 Ford Aspire


AIR BAG, (BEHIND GLOVE BOX) 1994 Ford Crown Victoria


AIR BAG, (EMERGENCY PEDAL) 1994 Ford E-150 Econoline


AIR BAG, (EMERGENCY PEDAL) 1994 Ford E-150 Econoline Club Wagon


AIR BAG, (EMERGENCY PEDAL) 1994 Ford E-250 Econoline


AIR BAG, (EMERGENCY PEDAL) 1994 Ford E-350 Econoline


AIR BAG, (EMERGENCY PEDAL) 1994 Ford E-350 Econoline Club Wagon


AIR BAG, (LH DASH) 1994 Ford Tempo


AIR BAG, (BEHIND FUSE PANEL) 1994 Mercury Capri


AIR BAG, (BEHIND GLOVE BOX) 1994 Mercury Grand Marquis


AIR BAG, (LH DASH) 1994 Mercury Topaz


AIR BAG, (LH STEERING COLUMN) 1993 Ford Aerostar


AIR BAG, (BEHIND GLOVE BOX) 1993 Ford Crown Victoria


AIR BAG, (EMERGENCY PEDAL) 1993 Ford E-150 Econoline


AIR BAG, (EMERGENCY PEDAL) 1993 Ford E-150 Econoline Club Wagon


AIR BAG, (EMERGENCY PEDAL) 1993 Ford E-250 Econoline


AIR BAG, (EMERGENCY PEDAL) 1993 Ford E-350 Econoline


AIR BAG, (EMERGENCY PEDAL) 1993 Ford E-350 Econoline Club Wagon


AIR BAG, (CENTER CONSOLE) 1993 Ford Mustang


AIR BAG, (LH DASH) 1993 Ford Tempo


AIR BAG, (BEHIND FUSE PANEL) 1993 Mercury Capri


AIR BAG, (BEHIND GLOVE BOX) 1993 Mercury Grand Marquis


AIR BAG, (LH DASH) 1993 Mercury Topaz


AIR BAG, (LH STEERING COLUMN) 1992 Ford Aerostar


AIR BAG, (BEHIND GLOVE BOX) 1992 Ford Crown Victoria


AIR BAG, (EMERGENCY PEDAL) 1992 Ford E-150 Econoline


AIR BAG, (EMERGENCY PEDAL) 1992 Ford E-150 Econoline Club Wagon


AIR BAG, (EMERGENCY PEDAL) 1992 Ford E-250 Econoline


AIR BAG, (EMERGENCY PEDAL) 1992 Ford E-350 Econoline


AIR BAG, (EMERGENCY PEDAL) 1992 Ford E-350 Econoline Club Wagon


AIR BAG, (CENTER CONSOLE) 1992 Ford Mustang


AIR BAG, (LH DASH) 1992 Ford Tempo


AIR BAG, (ABOVE GLOVE BOX) 1992 Lincoln Mark VII


AIR BAG, (BEHIND FUSE PANEL) 1992 Mercury Capri


AIR BAG, (BEHIND GLOVE BOX) 1992 Mercury Grand Marquis


AIR BAG, (LH DASH) 1992 Mercury Topaz
 
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