QuestionQUESTION: About a month ago i went to turn my rear defrosters on and i pushed the button in and nothing happened. The button itself would not click in and the light never came on. I did replace the fuse and i had no luck. Someone said something about a switch?? Could you please help!! I was also wondering how much this would run if i do need this "switch" replaced!! Thanks!
ANSWER: The defroster switch would be the button you've depressed.
Most Hyundai defoggers are controlled by an electronic time and alarm control module (ETACM) and will only operate when the car is running. Typical causes of the switch lamp not coming on are the following:
-- alternator not charging, making the ETACM think the car is not running
-- blown fuse-- I believe there are two that are necessary for the defogger to operate
-- defective or unplugged switch
-- defective ETACM.
The defogger switch is not designed to stay in. It's designed to have only momentary contact to send a request to the ETACM to turn on the defogger. A problem with your back glass or contacts could also cause the defogger to not work, but that wouldn't cause the indicator lamp to not come on.
You'll find that repair costs will vary greatly by the shop performing the repairs, the part manufacturer and supplier, and your geographic location. Once you determine which repairs are necessary, you may wish to call a few places near you to see what they'd charge for the work.
If you'd like, follow-up with the year and model of your car, and I'll tell you which fuses to check to be sure all the pertinent fuses are okay.
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QUESTION: Thank you so much you have been such a great help. Well my uncle looked at the little things on the back window and said they seem to be ok. And when i changed the fuse it still did not work. Also i had a new alternator put in about 2 years ago so i dont see why that would be a problem, but im a girl and 21 and really dont know much! I have a 2000 Hyundai accent 4 door. Its not a hatch back. I changed the number 10 fuse. Also i dont have AC in my car. It was never made with it. I dont know if that would change anything either. Thanks again!!!
AnswerYou'll need to diagnose the electrical circuits to diagnose the problem. The alternator is an easy enough check. Simply start the vehicle and place a voltmeter across the battery terminals. You should have at least 13.5V. If not, you'll need to check the charging system.
Checking to see whether the switch is plugged in is also simple. That's just a matter of disconnecting the heater control cables and pulling out the center dash panel to see if it's connected.
Beyond that, you'll need to be able to read a schematic and test whether the ETACM receives the signal from the switch and whether it energizes the defogger. You can view the schematics for your vehicle at www.hmaservice.com. You'll need to register for a free account, and the site requires Internet Explorer.
