Section 15-00: Audio Systems—Service
1994 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Electrical Schematics



Electronic Search Radio (ESR)






Connector End Views






Pin Number Circuit Circuit Function
1 54 (LG/Y) 12V Radio Memory
2 57 (BK) Ground
3 137 (Y/BK) 12V Power Feed
4 19 (LB/R) Instrument Dimming
5 — Not Used
6 694 (BK/LG) Ground
7 — Not Used
8 — Not Used







Pin Number Circuit Circuit Function
1 804 (O/LG) Left Front Radio Speaker Signal (+)
2 813 (LB/W) Left Front Radio Speaker Signal (-)
3 801 (PK/LB) Left Rear Radio Speaker Signal (-)
4 800 (GY/LB) Left Rear Radio Speaker Signal (+)
5 805 (W/LG) Right Front Radio Speaker Signal (+)
6 811 (DG/O) Right Front Radio Speaker Signal (-)
7 802 (O/R) Right Rear Radio Speaker Signal (+)
8 803 (BR/PK) Right Rear Radio Speaker Signal (-)



Electronic Stereo Cassette (ESC) with Premium Sound






Connector End Views






Pin Number Circuit Circuit Function
1 802 (O/R) Right Rear Radio Speaker (-) Output
2 802 (O/R) Right Rear Radio Speaker (+) Output
3 811 (DG/O) Right Front Radio Speakers (-) Output
4 805 (W/LG) Right Front Radio Speakers (+) Output
5 801 (T/Y) Left Rear Radio Speaker (-) Output
6 800 (GY/LB) Left Rear Radio Speaker (+) Output
7 813 (LB/W) Left Front Radio Speakers (-) Output
8 804 (O/LG) Left Front Radio Speakers (+) Output
9 — Not Used
10 — Not Used
11 — Not Used
12 689 (DB) Radio Chassis On Input
13 694 (BK/LG) Ground
14 37 (Y) 12V Power Feed







Pin Number Circuit Circuit Function
1 857 (W/O) Left Front Radio Speaker Signal (-)
2 859 (Y) Left Rear Radio Speaker Signal (-)
3 858 (BR) Right Front Radio Speaker Signal (-)
4 855 (LB) Right Rear Radio Speaker Signal (-)
5 280 (LG) Left Front Radio Speaker Signal (+)
6 277 (LB/BK) Left Rear Radio Speaker Signal (+)
7 279 (W/R) Right Front Radio Speaker Signal (+)
8 278 (P/W) Right Rear Radio Speaker Signal (+)







Pin Number Circuit Circuit Function
1 54 (LG/Y) 12V Radio Chassis Memory
2 57 (BK) Ground
3 137 (Y/BK) 12V Power Feed
4 19 (LB/R) Instrument Dimming
5 — Not Used
6 694 (BK/LG) Ground
7 — Not Used
8 689 (DB) Radio Chassis On Output







Pin Number Circuit Circuit Function
1 855 (LB) Right Rear Radio Speaker Signal (-)
2 278 (P/W) Right Rear Radio Speaker Signal (+)
3 858 (BR) Right Front Radio Speaker Signal (-)
4 279 (W/R) Right Front Radio Speaker Signal (+)
5 859 (Y) Left Rear Radio Speaker Signal (-)
6 277 (LB/BK) Left Rear Radio Speaker Signal (+)
7 857 (W/O) Left Front Radio Speaker Signal (-)
8 280 (LG) Left Front Radio Speaker Signal (+)



Electronic Stereo Cassette (ESC) with Digital Audio Compact Disc Player and Premium Sound






Electronic Stereo Cassette (ESC) with Digital Audio Compact Disc Player and Premium Sound (Continued)






Connector End Views






Pin Number Circuit Circuit Function
1 — Not Used
2 747 (O/LB) Radio On Input
3 54 (LG/Y) Power
4 19 (LB/R) Instrument Dimming
5 694 (BK/LG) Ground
6 57 (BK) Ground







Pin Number Circuit Circuit Function
1 849 (T) Logic Sense
2 799 (O/BK) Right Channel Signal Out
3 690 (GY) Right Channel Signal In
4 848 (DG/O) Processor Loop Signal Return
5 798 (LG/R) Left Channel Signal Out
6 856 (P) Left Channel Signal In







Pin Number Circuit Circuit Function
1 54 (LG/Y) 12V Radio Memory
2 57 (BK) Ground
3 137 (Y/BK) 12V Power Feed
4 19 (LB/R) Instrument Dimming
5 — Not Used
6 694 (BK/LG) Ground
7 747 (O/LB) Radio On Output
8 689 (DB) Radio On Output







Pin Number Circuit Circuit Function
1 855 (LB) Right Rear Speaker Signal (-)
2 278 (P/W) Right Rear Speaker Signal (+)
3 858 (BR) Right Front Speaker Signal (-)
4 279 (W/R) Right Front Speaker Signal (+)
5 859 (Y) Left Rear Speaker Signal (-)
6 277 (LB/BK) Left Rear Speaker Signal (+)
7 857 (W/O) Left Front Speaker Signal (-)
8 280 (LG) Left Front Speaker Signal (+)







Pin Number Circuit Circuit Function
1 849 (T) Logic Sense
2 799 (O/BK) Right Channel Signal (-)
3 690 (GY) Right Channel Signal (+)
4 848 (DG/O) Signal Return
5 798 (LG/R) Left Channel Signal (-)
6 856 (P) Left Channel Signal (+)







Pin Number Circuit Circuit Function
1 803 (BR/PK) Right Rear Speaker (-) Output
2 802 (O/R) Right Rear Speaker (+) Output
3 811 (DG/O) Right Front Speaker (-) Output
4 805 (W/LG) Right Front Speaker (+) Output
5 801 (T/Y) Left Rear Speaker (-) Output
6 800 (GY/LB) Left Rear Speaker (+) Output
7 813 (LB/W) Left Front Speaker (-) Output
8 804 (O/LG) Left Front Speaker (+) Output
9 — Not Used
10 — Not Used
11 — Not Used
12 689 (DB) Radio On Input
13 694 (BK/LG) Ground
14 37 (Y) 12V Power Feed







Pin Number Circuit Circuit Function
1 857 (W/O) Left Front Speaker Signal (-)
2 859 (Y) Left Rear Speaker Signal (-)
3 858 (BR) Right Front Speaker Signal (-)
4 855 (LB) Right Rear Speaker Signal (-)
5 280 (LG) Left Front Speaker Signal (+)
6 277 (LB/BK) Left Rear Speaker Signal (+)
7 279 (W/R) Right Front Speaker Signal (+)
8 278 (P/W) Right Rear Speaker Signal (-)



Premium Analog Cassette (PAC) with Super Sound System






Connector End Views






Pin Number Circuit Circuit Function
1 54 (LG/Y) 12V Radio Memory
2 57 (BK) Ground
3 137 (Y/BK) 12V Power Feed
4 19 (LB/R) Instrument Dimming
5 — Not Used
6 694 (BK/LG) Ground
7 — Not Used
8 689 (DB) Radio On Output







Pin Number Circuit Circuit Function
1 855 (LB) Right Rear Speaker Signal (-)
2 278 (P/W) Right Rear Speaker Signal (+)
3 858 (BR) Right Front Speaker Signal (-)
4 279 (W/R) Right Front Speaker Signal (+)
5 859 (Y) Left Rear Speaker Signal (-)
6 277 (LB/BK) Left Rear Speaker Signal (+)
7 857 (W/O) Left Front Speaker Signal (-)
8 280 (LG) Left Front Speaker Signal (+)



Premium Analog Cassette (PAC) with Digital Audio Compact Disc Player and Super Sound System






Connector End Views






Pin Number Circuit Circuit Function
1 — Not Used
2 747 (O/LB) Radio On Input
3 54 (LG/Y) Power
4 19 (LB/R) Instrument Dimming
5 694 (BK/LG) Ground
6 57 (BK) Ground







Pin Number Circuit Circuit Function
1 849 (T) Logic Sense
2 799 (O/BK) Right Channel Signal Out
3 690 (GY) Right Channel Signal In
4 848 (DG/O) Processor Loop Signal Return
5 798 (LG/R) Left Channel Signal Out
6 856 (P) Left Channel Signal In







Pin Number Circuit Circuit Function
1 54 (LG/Y) 12V Radio Memory
2 57 (BK) Ground
3 137 (Y/BK) 12V Power Feed
4 19 (LB/R) Instrument Dimming
5 — Not Used
6 694 (BK/LG) Ground
7 747 (O/LB) Radio On Input
8 689 (DB) Radio On Output







Pin Number Circuit Circuit Function
1 855 (LB) Right Rear Speaker Signal (-)
2 278 (P/W) Right Rear Speaker Signal (+)
3 858 (BR) Right Front Speaker Signal (-)
4 279 (W/GR) Right Front Speaker Signal (+)
5 859 (Y) Left Rear Speaker Signal (-)
6 277 (LB/BK) Left Rear Speaker Signal (+)
7 857 (W/O) Left Front Speaker Signal (-)
8 280 (LG) Left Front Speaker Signal (+)







Pin Number Circuit Circuit Function
1 849 (T) Logic Sense
2 799 (O/BK) Right Channel Signal (-)
3 690 (GY) Right Channel Signal (+)
4 848 (DG/O) Signal Return
5 798 (LG/R) Left Channel Signal (-)
6 856 (P) Left Channel Signal (+)



Super Sound System






Connector End Views






Pin Number Circuit Circuit Function
1 803 (DG/O) RH RR Radio Speaker (-) Output
2 802 (O/R) RH RR Radio Speaker (+) Output
3 811 (DG/O) RH FR Radio Speaker (-) Output
4 805 (W/LG) RH FR Radio Speaker (+) Output
5 801 (PK/LB) LH RR Radio Speaker (-) Output
6 800 (GY/LB) LH RR Radio Speaker (+) Output
7 813 (LB/W) LH FR Radio Speaker (-) Output
8 804 (O/LG) LH FR Radio Speaker (+) Output
9 — Not Used
10 — Not Used
11 — Not Used
12 689 (DB) Radio On Input
13 694 (BK/LG) Ground
14 37 (Y) 12 V Power Supply







Pin Number Circuit Circuit Function
1 857 (W/O) Left Front Speaker Signal (-)
2 859 (Y) Left Rear Speaker Signal (-)
3 858 (BR) Right Front Speaker Signal (-)
4 855 (LB) Right Rear Speaker Signal (-)
5 280 (LG) Left Front Speaker Signal (+)
6 277 (LB/BK) Left Rear Speaker Signal (+)
7 279 (W/R) Right Front Speaker Signal (+)
8 278 (P/W) Right Rear Speaker Signal (-)







Pin Number Circuit Circuit Function
1 48 Rear Speaker Amplifier Shield
2 172 (LB/R) Low Audio (-)
3 48 Front Speaker Amplifier Shield
4 168 (R/BK) High Audio (-)
5 — Not Used
6 — Not Used
7 174 (GY/BK) Low Audio Mute
8 169 (LG/BK) Low Audio (+)
9 173 (DG/P) High Audio Mute
10 167 (BR/O) High Audio (+)
11 — Not Used
12 — Not Used



Super Sound System (Continued)






Connector End Views






Pin Number Circuit Circuit Function
1 694 (BK/LG) Ground
2 694 (BK/LG) Ground
3 694 (BK/LG) Ground
4 37 (Y) 12V Power Feed
5 37 (Y) 12V Power Feed
6 37 (Y) 12V Power Feed
7 822 (BK/LG) Audio Out (+)
8 287 (BK/W) Audio Out (-)
9 — Not Used
10 — Not Used







Pin Number Circuit Circuit Function
1 — Not Used
2 173 (DG/P) Audio Mute
3 — Not Used
4 — Not Used
5 167 (BR/O) Audio Input (+)
6 168 (R/BK) Audio Input (-)







Pin Number Circuit Circuit Function
1 694 (BK/LG) Ground
2 694 (BK/LG) Ground
3 694 (BK/LG) Ground
4 37 (Y) 12V Power Feed
5 37 (Y) 12V Power Feed
6 37 (Y) 12V Power Feed
7 822 (BK/LG) Audio Out (+)
8 287 (BK/W) Audio Out (-)
9 — Not Used
10 — Not Used







Pin Number Circuit Circuit Function
1 — Not Used
2 174 (GY/BK) Audio Mute
3 — Not Used
4 — Not Used
5 169 (LG/BKBR/O) Audio Input (+)
6 172 (LB/R) Audio Input (-)