Defog Relay Control CKT Shorted To Batt

WARNING: This page is about a different car, the 2002 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

When Monitored:

With ignition on and Rear Window Defogger Switch depressed.

Set Condition:

When A/C-Heater Control Module senses excessive current on the Rear Window Defogger Relay Control circuit.

Possible Causes:

Check for HVAC DTCs.
Rear Window Defogger Relay shorted to battery.
Rear Window Defogger Relay Control circuit shorted to battery.
A/C-Heater Control Module.

CAUTION: Always turn ignition off before disconnecting or connecting any control module connector. Failure to do so could result in damage to control module.

NOTE: Ensure vehicle being tested has a fully charged battery. If it does not, false DTCs or error messages may occur.

NOTE: For component location, see appropriate illustration under COMPONENT LOCATIONS . For terminal identification, see appropriate illustration under CONNECTOR IDENTIFICATION . For circuit and wire color identification, see WIRING DIAGRAMS . For component removal and installation procedures, see appropriate component under REMOVAL & INSTALLATION .

Testing:

Turn ignition off. Connect DRBIII(R) to DLC. Turn ignition on. Using the DRBIII(R), read, record, then erase DTCs. Cycle ignition from off to on. Depress Rear Window Defogger Switch and wait approximately one minute. Using the DRBIII(R), read active DTCs. Does this DTC reset? If yes, go to next step. If no, visually inspect related wiring harnesses for any chafed, pierced, pinched or partially broken wires. Refer to any Technical Service Bulletin (TSB) that may apply. Visually inspect related harness connectors for broken, bent, pushed out or corroded terminals. Repair as necessary. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Turn ignition off. Substitute a known-good Rear Window Defogger Relay. Turn ignition on. Using the DRBIII(R), read, record, then erase DTCs. Depress Rear Window Defogger switch in A/C-Heater Control Module. Using the DRBIII(R), read active DTCs. Does this DTC reset? If yes, go to next step. If no, replace Rear Window Defogger Relay. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Turn ignition off. Remove Rear Window Defogger Relay from PDC. Disconnect A/C-Heater Control Module C1 harness connector. Measure voltage on the A/C-Heater Control Module C1 harness connector terminal No. 15. Is there any voltage present? If yes, repair the Rear Window Defogger Relay Control circuit for a short to battery. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, replace A/C-Heater Control Module. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.