2006 mustang gt no crank

[Miller Gt06]

Hello everyone! I have a 06 gt. I recently went on a 1 week vacation and came back to my car not starting. I went and bought a starter but my car randomly starter the next day. I drove it for a bit before it stopped starting again. I changed the starter but it didn’t do anything. I tried to jump it and that didn’t work either. I have a mechanic friend that cleaned the ignition and it started but wouldn’t start after a day. He recommends a new ignition switch.

All the electrical comes on when I turn my key to on. When I try to start it, there’s a single click noise coming from the inside fuse box.

 

[Forty61]

Auto or manual transmission?

If you're hearing things happen when you click the key to start I would guess the ignition switch is probably ok.

If starter is new and battery is good my next step would be to confirm the neutral/clutch switch is engaged properly. If that checks out then move on to the wiring to the starter, confirm when it should be starting if you've got 12V going out to the starter.

 

[asdrew]

fwiw once in a while my '06 GT auto doesn't even try starting when the key is turned (but all electrical turns on). Every time the issue is that the gear shifter sensor does not think it is in park, and jiggling it is all it takes to act normal.
When that area is eventually taken apart for upcoming mods, the switch will be adjusted or replaced.

 

[Kev555]

Try a diagnostic reader to see if anything pops up related to ignition or PATS.

 

[DieHarder]

Questions: Did you do any work recently? Have you done any modifications to the car? (It's often the case that modifications end up becoming current draws that will drain the battery after a week or so. They usually trace back to some sort of modification - LEDs/Stereo mods, etc). Is the battery fully charged? Is the starter relay good (engine fuse box; to test you can replace it temporarily with the Hi Speed Engine Cooling Fan Relay next to it in the BEC). Next, I'd check F21 (Starter Relay ckt; PCM Key Off relay; Clutch Pedal Position Switch) in the SJB.

When all else fails try the manual:

No DTCs: https://iihs.net/fsm/?d=9&f=Step 2-... Codes (DTCs) Present Symptom Chart Index.pdf Manual shows a chart 23 but can't find it in the online version. Long story short that chart says look at the anti-theft system (PATS) or the Starting system.

Engine - General Information: https://iihs.net/fsm/?d=143

Starting System - Diagnosis & Testing: https://iihs.net/fsm/?d=206&f=Starting System.pdf

Anti-Theft: https://iihs.net/fsm/?d=405

Good luck

 

[Steve W 06GT]

Try swapping out the starter relay for the horn relay and see if that changes anything. Definitely sounds like a relay or switch. You never mentioned if it was a manual or auto transmission. Could be a bad switch on the brake or clutch pedal or like asdrew said, if it's an auto trans it could be a bad/misaligned neutral/park safety switch. Hope you find the problem soon. My radio just completely went out and I've checked all the fuses which are all good so I'm on an electrical journey myself.

John 3:16