I have a 2003 Ford mustang with a 3.8L V6. The theft light stays on constantly, while either the car is off and the key is out, or running. I've tried the method of looking for codes in the dash. I get the image "dt3842" and then one more push of the odometer button it reads "dtc NONE". I also have a air bag light that flashes when ever it feels like it. Not sure if they are linked in some sort of way?
Theft light Stays on constantly
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I have a 2003 Ford mustang with a 3.8L V6. The theft light stays on constantly, while either the car is off and the key is out, or running. I've tried the method of looking for codes in the dash. I get the image "dt3842" and then one more push of the odometer button it reads "dtc NONE". I also have a air bag light that flashes when ever it feels like it. Not sure if they are linked in some sort of way?
I have a 2003 Ford mustang with a 3.8L V6. The theft light stays on constantly, while either the car is off and the key is out, or running. I've tried the method of looking for codes in the dash. I get the image "dt3842" and then one more push of the odometer button it reads "dtc NONE". I also have a air bag light that flashes when ever it feels like it. Not sure if they are linked in some sort of way?
I've merged your posts.
There's always a slight delay with brand new accounts while they are vetted by staff.
Welcome aboard!
I'll move this over to SN95.
There's always a slight delay with brand new accounts while they are vetted by staff.
Welcome aboard!
I'll move this over to SN95.
wmburns
SN Certified Technician
Does this car start and run? Or is this a crank with no start?
If this car does start and run, would you like an educated guess? How about a bad ignition switch? There are multiple gangs inside the switch and what happens sometimes is one of the gangs remains "ON" while others are "OFF".
There are tests that can be done to specific fuses to narrow down and/or confirm the diagnosis.
For example, with the key off, test for power in/out of fuse F2.5, and F2.34, If there is key off power in either fuse, the likely cause is a bad ignition switch.
1999-2004 MY fuse panel schedule:
www.allfordmustangs.com
1996+ Crank with no start check list
www.allfordmustangs.com
If this car does start and run, would you like an educated guess? How about a bad ignition switch? There are multiple gangs inside the switch and what happens sometimes is one of the gangs remains "ON" while others are "OFF".
There are tests that can be done to specific fuses to narrow down and/or confirm the diagnosis.
For example, with the key off, test for power in/out of fuse F2.5, and F2.34, If there is key off power in either fuse, the likely cause is a bad ignition switch.
1999-2004 MY fuse panel schedule:
1999 Mustang GT with 2001 motor swap, wont fire. Please help
First off thank you for taking the time to read this, I hope that you will be able to help me out in some way to get a 4 month project off the ground and back onto the streets. I'm not a master mechanic but know just a little bit, enough to do your typical maintenance, overhauls, and swaps. I...
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:
Yes, its starts and runs like normalDoes this car start and run? Or is this a crank with no start?
If this car does start and run, would you like an educated guess? How about a bad ignition switch? There are multiple gangs inside the switch and what happens sometimes is one of the gangs remains "ON" while others are "OFF".
There are tests that can be done to specific fuses to narrow down and/or confirm the diagnosis.
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
wmburns
SN Certified Technician
Updated original post with a link to the fuse panel schedule.
The other clue of a bad ignition switch is the battery drains with the key out.
And before you ask, changing an ignition switch is a DIY'er job and does NOT require PATS to be re-programmed.
Hey guys!
I am also having the same exact problem on my 1999 GT.
Some days my THEFT light stays on, but some days it stays off. It's seemingly random, but the car always starts. Sometimes the light goes away while I'm driving, but usually it either stays on or stays off.
I have tried disconnecting the battery for 20+ minutes. The light goes away, but eventually returns. That won't solve it
I have also tried turning the key to Accessory 8 times (as if you were going to program a new key fob). Same story
Some forums say that the THEFT light stays on when the PATS system has failed to engage. that makes sense to me, but I'm not an electrician.
I've also read that the THEFT light stays on when either your clicker (key fob) battery is dead, or your actual car battery is dead.
My plan is to change the key fob battery, and the car battery itself (also terminals, because it could just be a bad connection).
I've also bought a replacement Key Fob in case it is an issue with the one I have currently (although I highly doubt that)
I'm also going to have the mechanic change the ignition switch like you guys are discussing here
If one or a combination of all of these things fixes the problem I will come back and let you guys know.
This doesn't seem to be a super common problem, but there is literally not a single forum on the internet that tells you definitively how to fix this issue.
Let me know if you guys have any luck!
I am also having the same exact problem on my 1999 GT.
Some days my THEFT light stays on, but some days it stays off. It's seemingly random, but the car always starts. Sometimes the light goes away while I'm driving, but usually it either stays on or stays off.
I have tried disconnecting the battery for 20+ minutes. The light goes away, but eventually returns. That won't solve it
I have also tried turning the key to Accessory 8 times (as if you were going to program a new key fob). Same story
Some forums say that the THEFT light stays on when the PATS system has failed to engage. that makes sense to me, but I'm not an electrician.
I've also read that the THEFT light stays on when either your clicker (key fob) battery is dead, or your actual car battery is dead.
My plan is to change the key fob battery, and the car battery itself (also terminals, because it could just be a bad connection).
I've also bought a replacement Key Fob in case it is an issue with the one I have currently (although I highly doubt that)
I'm also going to have the mechanic change the ignition switch like you guys are discussing here
If one or a combination of all of these things fixes the problem I will come back and let you guys know.
This doesn't seem to be a super common problem, but there is literally not a single forum on the internet that tells you definitively how to fix this issue.
Let me know if you guys have any luck!
Okay, so after some trial and error I think that the Key Fob Battery and The actual Car Battery are not the issue.
Apparently, the chip inside of Ford Keys tends to go bad after 15-20 years or so. It's the same story with the actual transceiver unit inside of the steering column. (It looks like a black plastic ring with a wire attached to it, and it surrounds the actual ignition cylinder).
I'm going to the dealer to have them make brand new keys and also change out that transceiver unit.
If you change the transceiver you HAVE to reprogram the keys btw.
Apparently, the chip inside of Ford Keys tends to go bad after 15-20 years or so. It's the same story with the actual transceiver unit inside of the steering column. (It looks like a black plastic ring with a wire attached to it, and it surrounds the actual ignition cylinder).
I'm going to the dealer to have them make brand new keys and also change out that transceiver unit.
If you change the transceiver you HAVE to reprogram the keys btw.
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