Ford 2003 Mustang Workshop Manual page 3724

Key in OFF position.
Disconnect: GEM C201c.
Measure the resistance between driver window regulator
control switch C537 pin 8, circuit 991 (TN/LB), harness side
and GEM C201a pin 3, circuit 991 (TN/LB), harness side.
Measure the resistance between driver window regulator
control switch C537 pin 6, circuit 992 (WH/BK), harness side
and GEM C201c pin 14, circuit 992 (WH/BK), harness side.
Are the resistances less than 5 ohms?
D8 CHECK CIRCUIT 400 (LB/BK) FOR AN OPEN
Key in OFF position.
Disconnect: CJB Circuit Breaker 43 (20A).
Measure the resistance between driver window regulator
control switch C537 pin 15, circuit 400 (LB/BK), harness side
and CJB circuit breaker 43 (20A) output pin, circuit 400
(LB/BK).
Yes
INSTALL a new GEM.
REFER to Section 419-
10 . TEST the system for
normal operation.
No
REPAIR the circuit. TEST
the system for normal
operation.
Yes
REPAIR the power supply
to CJB circuit breaker 43
(20A). TEST the system
for normal operation.
No
REPAIR the circuit. TEST
the system for normal
operation.