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Toyota Like Auto-Headlight

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=144990
Printed Date: March 28, 2024 at 12:34 PM


Topic: Toyota Like Auto-Headlight

Posted By: noidea24
Subject: Toyota Like Auto-Headlight
Date Posted: November 28, 2018 at 12:26 AM

I've been driving the 98 Tacoma as backup while my Ford was down and realized a feature I REALLY wanted that's present in a few cars.

With the Toyota if I leave the headlights on and turn the key off, then the headlights get turned off automatically. To turn them on you can either flick the switch off and back on, or turn the key on.

This circuit has me stumped.
I could always just run a standard "ignition off-power to headlightswitch off" kind of circuit, but then the key has to be on for the headlights.

I have 12v, acc., Ground, and either main power to the headlight switch, or I can break output on the parking light and headlight wire outputs.

Any help would be appreciated.



Replies:

Posted By: geepherder
Date Posted: November 28, 2018 at 9:37 AM
If I understand you correctly, your headlights will automatically turn off if left on but they don't come on automatically, right?

If this is correct, look for a red/white wire at the headlight switch. With the headlight switch in the off position, you should read 12 volts. If you turn on the headlights this reading should drop to 0 volts.

posted_image

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My ex once told me I have a perfect face for radio.




Posted By: noidea24
Date Posted: November 28, 2018 at 9:45 AM
No, right now the Ford has no auto off.
If I leave the headlights on and get out then they stay on.


I want them to cut off with ignition, but j want to be able to cut them back on by switching the headlights off and back on.




Posted By: geepherder
Date Posted: November 28, 2018 at 12:37 PM
I thought you were trying to add that to the Tacoma. Disregard the above diagram then.

What is the year/model so we can help?

Alternatively, have you considered installing a buzzer to remind you the when the lights are on and the key off?

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My ex once told me I have a perfect face for radio.




Posted By: noidea24
Date Posted: November 28, 2018 at 3:07 PM
I'm working with a 99 f150.

Im not considering the buzzer because I don't really have a problem with leaving them on, I just really like the feature on the Toyota.



If headlight switch is on while key is turned off
Then the headlights cut off.

Then while the key is off and headlight switch on (but lights off)...
you turn the headlight switch off and back on then headlights come back on.
Or
You turn the key on, and the headlights come back on.


I've done a good bit of mods to this truck like...
Remote start
Keyless/alarm
Retained acc. Until door opened
Illuminated entry
All led interior and exterior (including ugly green interior lighting converted to white)
Inverter w/ ps2
4 channel
1 channel
Crossovers
Etc, and day to day my job for the past few years have been 12v technician, so I've got some experience.




Posted By: geepherder
Date Posted: November 28, 2018 at 11:13 PM
While not exactly the same, how about a time delay relay? I'm thinking you could connect it so if the switch is left in the on position and you kill the engine, it'll remove power after an adjustable amount of time. To restart the timer, though, you'd have to recycle the ignition.

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My ex once told me I have a perfect face for radio.




Posted By: noidea24
Date Posted: November 29, 2018 at 12:27 AM
The timer would work, but only if I could find a way to restart the timer by turning the headlight switch off and back on as well.


So key off-light on, timer keeps lights on for (2 minutes?) then the lights cut off.
After the timer cuts the lights off, I can turn the key on and back off to restart timer OR I can turn the headlight switch off and back on to restart timer




Posted By: geepherder
Date Posted: November 29, 2018 at 10:31 AM
posted_image

It works in my head, but it's untested. Maybe you can proofread it for me. You'll cut the headlight wire behind the switch (which I believe is red/yellow). R1 is a bleed resistor, 1K ohms or higher. You may need to try different values for C1. CR1/CR2 are standard switching diodes.

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My ex once told me I have a perfect face for radio.




Posted By: geepherder
Date Posted: November 29, 2018 at 5:54 PM
I was just thinking, you won't want to use this because some relays will stay energized if you leave the light switch on.

It'll drain the battery. An op amp would be a better choice.

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My ex once told me I have a perfect face for radio.




Posted By: geepherder
Date Posted: November 30, 2018 at 8:30 AM
Let's try this again:

posted_image

This will eliminate the excess current draw of the initial diagram.

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My ex once told me I have a perfect face for radio.




Posted By: eguru
Date Posted: November 30, 2018 at 10:38 AM
If you would be satisfied with extending the headlight on time by only 4 minutes and 15 seconds, the PAC TR7 would work for you.
It would simplify the construction process.

https://pac-audio.com/catalog/specialty-items/tr7




Posted By: geepherder
Date Posted: November 30, 2018 at 11:56 AM
Eguru's solution is brilliant.

I do want to add if you use the transistor/relay setup, make sure to up the value of the bleed resistor to 10K ohms or more to minimize constant current draw when the car is off with the light switch on.

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My ex once told me I have a perfect face for radio.





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