Will not start, how to reset factory alarm?

ROB 1503

MEMBER
2008 FORD MUSTANG
V6
2WD
AUTOMATIC
121,000 MILES

Hi,

My friend has been having issues with her car after installing both the battery and alternator. She went to turn in the car, and it started up right away but then she said that after maybe 30 seconds or so it turned off and it would crank over but wouldn't start until the next day. After trying again, the following day it did the same thing so I went over to see it for myself and it did the same thing only I did something different. After it shut off on me I don't know why I decided to not crank it again but actually arm and disarm the alarm and when I cranked it over it turned on but after a few seconds it turned off. So, I repeated the same thing. I did it about five times and Every time it did the same. So, I figured maybe it's the alarm that is activating the immobilizer and doing a factory alarm reset might fix it.

Rob

3 Replies

JACOBANDNICKOLAS

MECHANIC
108,300 POSTS

Hi Rob,

Does the security light stay on or flash when it won't start?

Next, do me a favor. When it fails to restart, check to see if the engine is getting fuel and spark. At least, that will help us narrow things down. See if it starts using starting fluid and then stalls. If it does, then we know it is fuel related.

If that makes no difference, follow this link to check for spark:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

If it does start with starting fluid and then stall, reset the fuel cut-off (inertia) switch. See pic 1 for location.

If that makes no difference, let me know. Check out the images (Below). Please let us know what happens.

Image (Click to make bigger)