No Start fixed (simple..after) Involved Ford Keyless system & stock ignition system
2007 S197 Mustang dead in the water for 3 days.
Death occurred upon pressing a remote start fob START button while a good key was in ignition, on ON.
The end of the story is embarrassingly simple. For the impatient or easily bored;
Fix = Fuse 68 (Ignition) in the BEC (Bused Electrical Center, or fuse block under the hood).
Some of the back story may help some other po'soul.
side confounding issue-
I had long ago installed a genyuwhine FoMoCo remote starter system; it worked as intended for a couple seasons, then (of course when it got cold enough to want to use it) a press on the Start button would initiate the start (lock doors, etc) then some fault was encountered and it would error out. beep beep beep I quit. I lived with it because it's a stone beeeeeee'ach to work on .
Fast forward to the fateful day; I had the ignition ON (dash lights lit, I think), but motor certainly OFF and the fancy remote start fob hanging on the inserted key. For not really much more than giggles I pressed the REMOTE START (blue key) button on the fancy fob, and the dash went dark as the warmer side of a hibernating bear. Except for that annoying PATS lock symbol blinking every 2 seconds (as in "armed / not tripped"). My original fobs would still unlock the doors & trunk & set off the panic horn, while the remote start fobs would not do anything.
None of my several keys would start it or do anything at all, for that matter. Great; one window half way down, gearshift locked in park, fortunately the ragtop was up, or probably would have a modular V8 swimming pool given the weather the next few days.
1st Free tip - with no key response, the gearshift is interlocked in park, so I couldnt even push the car out of the yellow zone! Thanks Henry, you suck. I find out later (after jacking the car onto garage dollies and dragging it across the parking lot like a drunken roller skater to a better resting place) that the itty bitty chrome shiny oval pop out cover - next to the shifter - is what you lever out to push a key or some such down in to release a stuck up shifter. The things I didn't learn in school ...
Now I had lost the horn function at the wheel a week or so before (horn still chirped after fob lock/lock, thus horn was not 100% fried) so I sort of prematurely conjectualted the problem could be a steering column wire issue (like from wheel tilting) or maybe a PATS transceiver ring issue, maybe a starter switch. Bad guesses. I mean, yeah the dash lights sure died like a fuse did it and I could almost swear I heard the tiny pop or maybe just a solenoid clink somewhere or maybe it was my heart stopping for a momo and there was that button press thingy possibly co-incident but why the heck would the act of starting the car in a cross eyed fashion be a problem?
Troubleshooting tips implied to disconnect (non Ford) remote starters first, so after I dragged my 28,000 mile paperweight home, I decided the opportunity had knocked to royally redo & fix the remote start at the same time. I suspected problems with the crimp on + spade connectors I had used originally.
Pulled most of the the dash plus the steering wheel to rewire. Heres my next tip - If you are installing a remote starter and are a) more than 4 feet & 80 lbs of finely honed mechanical smug-ness or b) dont have short baby t-rex arms & a spine like a warm jello slinky, then removing the steering wheel along with all the dash panels is WELL worth the extra effort, helping out my Remote Start ReDo v.greatly by allowing sit up work mostly while removing those crimp-ons and doing a proper cut+crimp+solder+shrink-wrap & bobs your uncle on the dozen or so knee-wall wire harness connections. More things not learned in school.
I found a broken horn wire (dk blue ), which was definitely from the crimp-on/spade taps. I really like those things when I can partially strip the wire then solder on for added security, and did that to as many as I could but more were just too damn inconvenient first time as I am not a) or b) above so c) I was working upside down in a northwest mountain February. Like hell I wanted to solder right over my frosty red runny nose so I settled for the less secure partially strip & clamp on for a good many (the taps are made to slice into the insulation when closing but I really dont trust that to go well 25 times in a row). Suffice to say that the crimp-on wire taps DID eventually break two of the fine ~22g wires ... well after the fact too (as horn wire broke years later).
After all that, still no luck when trying the key - same damn PATS Lock Light blinking like the idiot light it is. It did previously bother me that yanking SJB fuse 19 (supposed to be the PATS fuse, which was not blown) did not stop the PATS dash light from its seductive come hither wink. This must be as intended. Illogical to me.
Probing fuse 19 showed no volts. Getting somewhere. Time to dig up the wiring diagrams.
Now heres the most important part;
Turns out that SJB fuse 19 is fed through BEC fuse 68 ... namely the Ignition (!) fuse. OK I know somebody wants to say it - duh.
That fuse 68 b'tard was the blown one. (Not even fuse 69, which would mean they both get blown, I guess.) Brilliant, Henry double fused the circuit - and the BIGGER one blew ! I had previously found a bad fuse in the remote starter brain box, opps dont know which one, which was encouraging but possibly misleading.
Finally to the finger pointing stage, I conclude that hitting the remote starter START button , WITH the ign key in and ON, caused the IGNITION fuse to blow, killing everything from there, down through the SJB, over to the key, killing all the dash lights and the PATS system, along with a couple of my last free days before winter descends like a ton of nasty gritty margarita .
PS I talked to a couple stealerships, to see what parts were stocked in town before I started testing, and one otherwise helpful & somewhat knowledgable jockey guessed it was most likely a PCM/PATS brainfart = loss of PATS key code, and I should simply TOW the car in and signup for the first possible $300 of labor, and maybe get out cheap with just a code read & key re-program. The other stdealer service guy couldnt wait to quit listening to the play by play and was markedly less helpful, probably licking his chops at selling a new $900 PCM to a guy with a bad 20A fuse.
Neither one suggested what should seem obvious ( to me, now, and to someone smharder & supposedly more experienced, much earlier on), that it might be THE STINKING IGNITION FUSE under the hood that can take the whole car down in 10 different aspects.
oh well, I can feel better for being slightly less stupid & out 45 cents cash, than remaining brick-thick and out hundred$ at the least.
To repeat, my big tip is to check that BEC/IGN fuse#68, next check SJB#19 PATS fuse, very early in your auto'psy after sudden pony death.
Hey we see I really beat the hell out of this topic, mainly since I first looked all over the wwweb for clues and came up very short on insight.
If you enjoyed it, feel free to solve your own problem and excruciatingly detail it for our children's children ( working on then "classic" 197 mustangs converted to nat gas or plutonium giga reactors.) .
extra googly terms - S197 no start, passive anti theft , securilock codesystems