Auto headlights not shutting off
#1
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Hi all, haven't posted in a while about my 98 LS400. I recently started having an issue with the auto headlights not shutting off after leaving the car.
I know the first thought would be door, trunk, hood sensors. Tested all of them and they work normally. Open door/trunk/hood indications in the cluster also work normally.
Here's the most interesting part -- even with a door ajar, you can normally kill the lights by arming twice. This no longer works... the lights stay on no martter how many times you arm.
They turn on/off normally while driving depending on light level -- they only stay on and refuse to extinguish when shutting down after dark, and will run the battery completely flat unless manually shut off.
Thanks for any clues!
I know the first thought would be door, trunk, hood sensors. Tested all of them and they work normally. Open door/trunk/hood indications in the cluster also work normally.
Here's the most interesting part -- even with a door ajar, you can normally kill the lights by arming twice. This no longer works... the lights stay on no martter how many times you arm.
They turn on/off normally while driving depending on light level -- they only stay on and refuse to extinguish when shutting down after dark, and will run the battery completely flat unless manually shut off.
Thanks for any clues!
#3
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Sounds like a problem in the headlight delayed turn off circuit; I'm not sure if it uses a physical relay, or a solid-state control, but it's stuck on, which bypasses all the other controls, except the OFF switch.
Last edited by fixmiester; 11-07-17 at 04:48 AM. Reason: Clarifying
#7
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#8
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At first I'd check the relay's contacts to see how one side is convex (pip) and the other concave (crater). I have seen many relay problems such as a situation of dog's intercourse.![Big Grin](https://www.clublexus.com/forums/images/smilies/biggrin.gif)
This is common problems among aged DC relay's contacts that carry big current.
![Big Grin](https://www.clublexus.com/forums/images/smilies/biggrin.gif)
This is common problems among aged DC relay's contacts that carry big current.
Last edited by Yamae; 11-08-17 at 11:43 PM.
#9
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"situation of a dog's intercourse" . Never ran across that one before, although I've often filed relay contacts to remove deposition fouling deposits. Wish I could find an emoji for that!
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