HELP! Please
 

Just recently bought 1999 Mustang GT 4.6L 5 speed from a private owner and had the car for several months now. Here is what we were told when it was purchased:
was told it was a 5.4 (but its actually 4.6)
cams have been changed to next step up from stock
Higher flo injectors
flowmasters with x pipe
aftermarket throttle body
Computer tuned for changes and car needs to be run on 93 octane

This vehicle had a red wire running across the firewall to the passenger side and don near the accumulator (guy told us it was for radio memory) which didn't sound right.

Long story short, car has been running great for 2 months until that red wire came undone. The red wire was run to a switch under the dash which had key power from the fuse panel. Car will no longer run (have no injector pulse)
Tried having keys reprogrammed but locksmith says his reader states "fault" and can not read code for key. Ive also tried my snap on scanner and it will not communicate either.

Any ideas?? I have no clue where that red wire could have been tapped into, but im guessing it was powering the injectors. Any help is appreciated ive been working on this for 3 days with no luck!

sounds like you lost 12v constant to pcm, pull the passenger side kick panel out and look to see if that red wire comes into there any place.

what do you get on the dash when you turn the key to run? you should get all lights for a moment. If your cel does not illuminate for a moment then the pcm is not getting 12v constant

when i put the key in and turn to the on position i get the abs light and the theft light blinks slowly. that home made red wire from the previous owner was powered with key on, but did not have power in the crank mode. He also said that wire was connected somewhere in the engine compartment but did not know where. he also said the guy before him said that wire had to be added because of the higher lb fuel injectors (which doesnt make sense)
When i try to crank the car and return the key to the on position, then the CEL illuminates but I cant pull any codes