Ford AM/FM stereo Owner's Manual page 150

Roadside Emergencies
The relays are coded as follows:
Relay location
1
2
3
4
Engine compartment relay module
The engine compartment relay module is located in one of two places
depending on which type of engine your vehicle is equipped with:
• Gasoline engine: driver side of the engine compartment above the
brake master cylinder.
• Diesel engine: passenger side of the engine compartment behind the
power distribution box.
Have a certified technician or your dealer service this module, if
required.
The relays are coded as follows:
Relay location
1
2
3
4
150
Description
Interior lamps
Open
Roof marker lamps
Battery saver
Description
Trailer tow left turn
A/C control
PCM back-up lamp
Trailer tow right turn