need help engine shutting down

08GT500 said:

Hi, Sounds like an EEC Relay issue to me. If you’re losing 100% percent power, (engine stall & Dash Power) while Driving, Key-switch replaced, I’d be looking that direction.
Take the opportunity to clean your Battery terminals and verify all of your Grounds are solid, Battery to EEC, Battery to Block, Block to Chassis Strap.
Replace wiring/connectors that you may have been putting off (if any) or appear any less than optimal. T.Moss drafted up an easy to understand layout of the basic electrical System. I’d added the link below.
Any questions, don’t hesitate.
Good luck!

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

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