selinapeters10
SC rear defroster malfunction
Summary of the thread
The conversation centers around a malfunction in the rear defroster of a 2010 Lexus SC, with diagnostics indicating a heavily discharged or defective battery as a potential cause. A similar issue was experienced by another individual, who suggested checking the battery and thermal window fuse. The problem was resolved by replacing the defective battery, restoring the rear window heating functionality.
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4 comment(s)
selinapeters10 (community.author)
Thank you for the quick response. I did check the fuse, it appears to be intact. Could a weak battery truly cause such a specific failure in the window demister circuit? Is there a specific voltage threshold I should be looking for?
elizabeth_wolf54
Yes, a weak battery can definitely cause that. The rear window heating and windshield heating draw a lot of power. If the voltage drops too low, the system might throw an error and shut down. I'd suggest taking it to a workshop to get the battery properly tested, and maybe the charging system too.
selinapeters10 (community.author)
Understood. Thank you for confirming my suspicions. I will proceed with a battery replacement. The workshop confirmed the battery was defective and performed the replacement; the rear window heating is now functional. Total cost was 290€.
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LEXUS
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SC
elizabeth_wolf54
I had a similar issue on my SC. The rear window heating coil wasn't working, and I was getting errors. Check your battery first, a weak battery can cause all sorts of electrical gremlins in these cars. Did you check the thermal window fuse?