Auto headlights not shutting off
11-06-17, 01:36 PM
#1
Intermediate
Thread Starter
Auto headlights not shutting off
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!
11-07-17, 04:46 AM
#3
Relay issue
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
11-08-17, 07:00 PM
#7
Lexus Champion
Trending Topics
11-08-17, 10:13 PM
#8
Moderator
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.
This is common problems among aged DC relay's contacts that carry big current.
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.
11-09-17, 05:45 AM
#9
Need to Google that
"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!
11-09-17, 06:37 AM
#10
Thread
Thread Starter
Forum
Replies
Last Post