Test Z

PINPOINT TEST Z: THE TRAILER LAMPS ARE INOPERATIVE

Test Z1:

Test Z1-Z3:

Test Z3-Z6:

Test Z6-Z7:

Normal Operation
Power is supplied to the trailer tow relay from circuits 29S-LF5A (OG/BU) and 30-ND3 (RD). Ground for the trailer tow relay is provided be circuit 31-ND3 (BK) and then through circuit 31-ND16A (BK). When the trailer tow relay is energized, power is switched to circuit 30S-ND5 (RD/BU). Circuit 30S-ND5 (RD/BU) is spliced and voltage is carried to the trailer tow auxiliary junction box (AJB) through circuits 30S-DC1 (RD/BU) and 30S-DC4 (RD/BU). After passing through two fuses (one for each circuit), voltage from the trailer tow AJB is then carried to the trailer tow module through circuits 30S-ND16A (RD/BU) and 30S-ND16B (RD/BU). Ground for the trailer tow module is through circuit 31-ND16 (BK). Ground for the trailer is provided through circuit 99-ND9 (WH/BU).

Possible Causes
- circuit 29S-LF5A (OG/BU) open
- circuit 30-ND3 (RD) open
- circuit 30S-DC1 (RD/BU) open
- circuit 30S-DC4 (RD/BU) open
- circuit 30S-ND5 (RD/BU) open
- circuit 30S-ND16A (RD/BU) open
- circuit 30S-ND16B (RD/BU) open
- circuit 31-ND3 (BK) open
- circuit 31-ND16 (BK) open
- circuit 31-ND16A (BK) open
- circuit 99-ND9 (WH/BU) open
- trailer tow relay
- trailer tow module
- trailer