If it's the factory PATS system: There's no reset switch. Problems are usually addressed by:
* Key Issues: The most common cause of PATS problems is a faulty key, or the key's transponder chip failing. A locksmith specializing in car keys can reprogram or replace keys.
* Battery: A weak battery can sometimes trigger the system. Try replacing the battery.
* Electrical Issues: A short circuit or other electrical problem might interfere. This requires a professional diagnosis.
If it's an aftermarket security system: The location of any reset switch will vary wildly depending on the brand and model of the system. Check the owner's manual for the aftermarket system (if you have it). It might be located:
* Under the dash: A common location, often hidden behind panels.
* In the glove compartment: Less common, but possible.
* Under the hood: Less likely, but some systems might have a switch there, often hidden.
* In the trunk (rare): This is less likely for a Mustang.
In short: Without knowing if your Mustang has a factory or aftermarket system, the location of a "reset switch" cannot be pinpointed. If it's a factory PATS system, there's no such switch. Start by checking your key and battery before attempting anything else. A professional mechanic or locksmith is best equipped to diagnose and fix persistent security system problems.
