if you can, solder and heat shrink the wires. It will save headaches in the future. If there isn't room to solder, use some butt connectors and crimp them tightly and then use electrical tape to tape up all the crimped wires. This will help too:
1992-93 Ford Mustang Security Information
Constant 12V+ Yellow Ignition Switch Harness
Starter White/Pink or Red/Blue Ignition Switch Harness
Ignition Red/Light Green Ignition Switch Harness
Accessory Gray/Yellow Ignition Switch Harness
Tach Tan/Yellow Coil
Neutral Safety Wire Not Grounding OEM Switch opens Starter Circuit
Brake Switch Red/Green Brake Switch
Trunk Release Purple/Yellow (+) Switch
Trunk Pin n/a Works with Dome Light
Parking Lights Brown (+) Light Switch or Driver's Kick Panel
Head Lamp Red/Yellow (+) Light Switch
Hood Pin n/a
Factory Disarm n/a
Door Trigger Black/Blue (+) Pin Switch or Courtesy Light
Door Lock Pink/Yellow Driver's Kick Panel
Door Unlock Pink/Green Reverse Polarity
Horn Wire Yellow/Light Green (-) Steering Column
Windows Up LF=White/Black, RF=White/Yellow, LR=Yellow/Blue, RR=Yellow/Blue
Windows Down LF=Yellow, RF=Tan/Blue, LR=Gray/Orange, RR=Red/Black