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I've always liked the idea of courtesy lights at night, especially in areas where there are few or no streetlights. Here's how I added a Delay Off feature to my Daytime Running Lights (DRLs) so that at night when I turn the clearance lights off, the DRLs will stay lit for awhile, then automatically turn off.
(This mod took place Oct 22, 2013.)
I got this 12 volt power off delay timing unit from eBay for $4.99 including shipping. You can also get this unit from Amazon. The relay contacts are rated for 10 amps at 250vac, 125vac, 30vdc, or 28vdc. There is a red LED to indicate power, and a green LED to indicate the timer operation. As you can see the unit is fairly compact (a US quarter is shown for comparison).
Here's are other views of the unit. It did not come with directions so I asked my coworker (an Electrical Engineer) to figure out how it works.
By examination and trial and error he was able to figure out that the S1, S2, and S4 jumpers set timing ranges, and the variable resistor allows fine-tuning of the timing interval. I chose a timer interval of about 45 seconds. Jumper S5 (optional) connects the incoming +12 volt screw terminal to the relay common. The pin closest to the ground connection is the trigger input. At left are the jumper settings he found (he did not try all possible jumper settings).
Shown at right is how I wired the unit. I disabled the red LED to eliminate current draw when the unit is not active. Different timer intervals can be chosen by using jumper settings other than shown.
In the daytime, the DRLs function as normal. At night, when the parking lights are turned on, the unit is activated and the DRLs are powered on but dimmed (see Chapter 15 for how I did that). When the parking lights are turned off, the dimmer is deactivated and the unit continues to feed power to the DRLs which are now at full brightness. The countdown starts and about 45 seconds later, the unit turns the DRLs off.
These pictures show the timing sequence (shots taken using shutter priority 1/40 to better portray darkness):
1. Headlights off, Parking lights on, DRLs dimmed.
2. Lights off, exit car. Puddle and dome lights on, DRLs full bright.
3. About 15 seconds after exit, puddle and dome lights turn off.
4. About 45 seconds after Parking lights off, DRLs turn off.
This mod is not flashy or obvious, but instead is an inexpensive little convenience nicety that works seamlessly, personalizes my ride, and most importantly, brings a smile to my face.
By the way: shown on the right is how you could add this unit to enable a Delay Power Off for your headlights. Just four new wires and you're in business.
Be sure to splice in the unit between the OEM headlight switch and the OEM headlight relay, so that the OEM headlight relay continues to handle the heavy current load to the headlights.
(Caution: the unit will not turn off the headlights if the headlight switch is left in the "ON" position. This unit is for Delay Power Off, not Automatic Off.)
Next: Rear Ended
You can send your questions or comments to BrickPig2011xb@gmail.com
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