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  • 1996 - 2004 SN95 Mustang -General/Talk-

theft light flashing no start sometimes

  • Thread starter Thread starter 03sonicvert
  • Start date Start date Aug 9, 2019
0

03sonicvert

New Member
Aug 9, 2019
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myrtle beach
Aug 9, 2019
#1
  • Aug 9, 2019
  • #1
I was wondering if anyone could help me with this problem my car is having. Some days my car runs perfect wihtout a single problem and then other days whenever im driving my theft light starts flashing then the car starts to sputter and jerk and while that happens all the lights on my dash start to flicker on and off. And usually whenever that happens the next time I go to start my car its like it is dead and the theft light flashes. Ive had both the battery and alternator checked out and they test perfect. If anyone has any advice it would be greatly appreciated thanks.
 

wmburns

SN Certified Technician
Aug 14, 2009
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Houston Texas
Aug 9, 2019
#2
  • Aug 9, 2019
  • #2
Ford factory PATS will not disable the motor once the motor has started. With that thought in mind the blinking theft light is not THE problem but a symptom of the problem.
03sonicvert said:
then the car starts to sputter and jerk and while that happens all the lights on my dash start to flicker on and off.
Click to expand...
^^^This is the important clue^^^ My vote is there's some power "issue" that is "causing" the PCM and ignition to "sputter".

This same power problem is also rearing it's head that prevents the motor from restarting. Remember that it takes a data exchange between the PCM and cluster. Sooooooooooooo if there's a problem either in the cluster or PCM this will cause the PATS exchange to break down.

If this were my car I would start with a through review of the battery and charging system. Don't stop at just looking at the battery and alternator. Review all of the connections and grounds.

Howto perform charging system voltage drop test

Howto perform charging system voltage drop test

To anyone else reading any of my posts I usually include the line: Today's cars simply will not run right without a strong battery and charging system! Cut corners here at your own risk I'm a big believer in starting with the basics. As such I...
www.stangnet.com

When you are sure that the charging system is in tip top shape, now we need a way to monitor the voltage while the car is moving. Suggest getting yourself an "add a circuit" this will offer a way to attach a VOM where it can be placed where it can be seen while driving. For example fuse F2.2 or F2.8. Testing here will give an idea of the function of the CCRM.

1999-2004 MY fuse panel schedule:

1997 mustang wont ignite

Hello lets start with I have a 97 mustang gt v8 standard I had new engine transmission ect put all new well last month i shut the car off and had no power at all bought a new battery and alternator got all power back but it wont ignite brought to mechnic for a month all sensors codes ect are fine
www.allfordmustangs.com

1996+ Crank with no start check list

1997 mustang wont ignite

Hello lets start with I have a 97 mustang gt v8 standard I had new engine transmission ect put all new well last month i shut the car off and had no power at all bought a new battery and alternator got all power back but it wont ignite brought to mechnic for a month all sensors codes ect are fine
www.allfordmustangs.com
 
Last edited: Aug 10, 2019

Decipha

Active Member
Aug 22, 2007
221
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39
New Orleans, LA
Aug 9, 2019
#3
  • Aug 9, 2019
  • #3
I would suspect a faulty ignition switch first or at least rule it out

theres also a chassis ground up by the battery that will do this as well
 
N

Necoler1

New Member
Nov 27, 2019
1
0
1
30087
Nov 27, 2019
#4
  • Nov 27, 2019
  • #4
03sonicvert said:
I was wondering if anyone could help me with this problem my car is having. Some days my car runs perfect wihtout a single problem and then other days whenever im driving my theft light starts flashing then the car starts to sputter and jerk and while that happens all the lights on my dash start to flicker on and off. And usually whenever that happens the next time I go to start my car its like it is dead and the theft light flashes. Ive had both the battery and alternator checked out and they test perfect. If anyone has any advice it would be greatly appreciated thanks.
Click to expand...
Did you find a solution? My 2004 is doing the exact same thing. Theft light was flashing car sputtered and jerked off when backing into garage. Theft light stays blinking car wont start. Tried turning wheel, rubbing fobs against stereo speaker and locksmith came out and reset keys. Car still wont start.
 

Potomus Pete

I'm still waiting for the fully nude shots
5 Year Member
Mar 7, 2019
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Sarasota Florida
Nov 27, 2019
#5
  • Nov 27, 2019
  • #5
This guy joined , asked the question , and never returned . All in one day . When possible, it is important to give a full explanation of what the fix was . Electrical problems stink .
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Nov 27, 2019
#6
  • Nov 27, 2019
  • #6
Necoler1 said:
Theft light was flashing car sputtered and jerked off when backing into garage. Theft light stays blinking car wont start. Tried turning wheel, rubbing fobs against stereo speaker and locksmith came out and reset keys. Car still wont start.
Click to expand...
Are you looking for an educated guess?

Your problem is NOT anti-theft (PATS) related. How do I know? Because Ford factory PATS will NEVER shut off the motor once it has started.

IMO you should look at a PCM base electrical problem first as the cause. Remember that PATS requires a two way exchange of data between the cluster and PCM. So IF something interrupts power to the PCM while the car is in motion that would cause the motor to stumble. Plus this could also re-drive the PATS exchange.

1996+ Crank with no start check list

1997 mustang wont ignite

Hello lets start with I have a 97 mustang gt v8 standard I had new engine transmission ect put all new well last month i shut the car off and had no power at all bought a new battery and alternator got all power back but it wont ignite brought to mechnic for a month all sensors codes ect are fine
www.allfordmustangs.com

Pay attention to the role that:
  • A loose PCM or CCRM ground could play in the symptoms
  • The role that a bad ignition switch could play. IE, check fuse F2.34.
 
Last edited: Nov 27, 2019
2

232937

New Member
Jun 10, 2019
20
0
1
palm springs ca
Feb 18, 2020
#7
  • Feb 18, 2020
  • #7
03sonicvert said:
I was wondering if anyone could help me with this problem my car is having. Some days my car runs perfect wihtout a single problem and then other days whenever im driving my theft light starts flashing then the car starts to sputter and jerk and while that happens all the lights on my dash start to flicker on and off. And usually whenever that happens the next time I go to start my car its like it is dead and the theft light flashes. Ive had both the battery and alternator checked out and they test perfect. If anyone has any advice it would be greatly appreciated thanks.
Click to expand...


DUDE I had the same problem and I know you said the battery was fine but get a new battery then see what happens im 90% sure you will solve your problem ny battery tested ok also..
 
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