Ha, ha, ha.
You have a BS in CS? Is that Hardware/ Software/ Computer Engineering?
Care to sight YOUR source. Ha, ha, ha.
I have
1) Ford Air Bag Systems Diagnostic Supplement Manual
2) Ford Service CD
3) Ford Service DVD
4) Ford hardcopy manuals.
For the FORD MUSTANG cars made on PLANET EARTH Air bags systems that have the battery backup (
1990 & 1991):
WARNING: ALL COMPONENT REPLACEMENTS AND WIRING SERVICE MUST BE MADE WITH THE NEGATIVE BATTERY CABLE DISCONNECTED FOR A
MINIMUM OF 20 MINUTES BEFORE SERVICE OR REPLACEMENT IS ATTEMPTED.
For the FORD MUSTANG cars made on PLANET EARTH Air bags systems that have the capacitor backup (
1992-1995+):
WARNING: THE BACK-UP POWER SUPPLY ENERGY MUST BE DEPLETED BEFORE ANY AIR BAG COMPONENT SERVICE IS PERFORMED. TO DEPLETE THE BACK-UP POWER SUPPLY ENERGY, DISCONNECT THE NEGATIVE BATTERY CABLE AND
WAIT ONE MINUTE TO AVOID ACCIDENTAL DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
Plus, if you short something out,
THE AIR BAG WILL *NOT* DEPLOY!!!!!
Geez! Look at the diagrams! You have a crash sensor and a safety sensor isolating power to the air bag. Also, the air bag connector has a shorting plug on it to help prevent static build-up when it's not connected to an air bag.
You want to be *safe* when taking out an air bag and putting on it. ANY electronic device can fail at ANY time. The air bag diagnostic controller uses
very low current and voltage to monitor the air bag. Also, in REAL life people are horrible about taking the proper static precautions. So, having a disconnected battery means that the air bag diagnostic controller wire are at "near ground". So, that means the both of the air bag wires are at "near ground". That add a little extra protection against static. Plus, you don't want to disconnect the air bag with the sense current goingf through it just in case the diagnostic monitor goes bad from a static shock that it would get when you touch the wires.
Joe
BS CS-hardware Engineering (in the engineering department, not in the math department)/EE (Elec Engr) (dual major),
MS CE (Comp Engr)
"3/4ths" ME (Mech Engr)
Partial PhD CE (Comp Engr) (I left for a great job opportunity that I couldn't pass up.
)
Foolish newbie engineers.