defrost: mirrors and rear are not working
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Rob
DodgeCares
#7
See if you're getting power to both sides of the fuse (fuse 36, 30A) when the rear defrost is turned on. There is a rear defrost relay that should provide power to the fuse. If that relay is bad or not making a good connection, the rear defrost will not get power even if Fuse 36 is good. This, however, would not explain why the heated mirrors don't work, but one step at a time.
The passenger heated mirror is controlled via the Passenger Door Module which is controlled via the CAN bus. Similar story for the driver's side heated mirror, controlled via the Driver's Door Module and CAN bus. There are separate fuses for each door module, but if those fuses were bad, a lot more with the mirrors and doors would fail to work than just the heater.
-Rod
The passenger heated mirror is controlled via the Passenger Door Module which is controlled via the CAN bus. Similar story for the driver's side heated mirror, controlled via the Driver's Door Module and CAN bus. There are separate fuses for each door module, but if those fuses were bad, a lot more with the mirrors and doors would fail to work than just the heater.
-Rod
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#8
have the battery tested and the battery state of health parameter checked with the scan tool. if you have stop/start that has 2 batteries...isolate them and test them individually.
your vehicle has an intelligent battery sensor. If it detects the battery state of health is low...the computer will start load shedding. the defroster is a high electrical load item but its not vital to vehicle operation. the system decides its more important to be able to start and drive the car vs risking a no crank so it disables high load items.
if you replace the battery without clearing the old battery data...it will take 2 days for the ibs to learn the new state of health. ie. it may not work for 2 days after replacing a bad battery..
your vehicle has an intelligent battery sensor. If it detects the battery state of health is low...the computer will start load shedding. the defroster is a high electrical load item but its not vital to vehicle operation. the system decides its more important to be able to start and drive the car vs risking a no crank so it disables high load items.
if you replace the battery without clearing the old battery data...it will take 2 days for the ibs to learn the new state of health. ie. it may not work for 2 days after replacing a bad battery..
Last edited by primem; 01-31-2020 at 03:20 AM.