E 450 V8-6.0L DSL Turbo (2007)
P7 Continued
Normal Operation
The trailer tow battery charge relay coil is provided voltage by the central junction box (CJB) fuse 15 (5A) through circuit 295 (LB/PK) when the
ignition switch is in the ACC or RUN position. Ground for the trailer tow battery charge relay coil is provided through circuit 57 (BK). Voltage for the
trailer tow battery charge relay switch side is provided by the battery junction box (BJB) fuse 8 (40A) through circuit 175 (BK/YE). When the trailer
tow battery charge relay is energized, voltage is routed to the trailer tow connector through circuit 49 (OG).
Possible Causes
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Fuse
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Circuit 49 (OG) open or short to voltage
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Circuit 57 (BK) open
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Circuit 175 (BK/YE) open
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Circuit 295 (LB/PK) open
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Trailer tow battery charge relay
-
Trailer
Test Q: The Trailer Electric Brakes Are Inoperative/Do Not Operate Correctly
PINPOINT TEST Q: THE TRAILER ELECTRIC BRAKES ARE INOPERATIVE/DO NOT OPERATE CORRECTLY
