| Questions about Daytime Running Lamps DRL [message #318254] |
Tue, 30 May 2017 23:09  |
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SteveW
Messages: 538
Registered: June 2005
Location: Southern California - Ora...
Karma: 1
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Greetings !!
I'm planning on installing some new LED headlights and they include "angel eyes" rings that function as daytime running lamps.
None of our current vehicles have DRLs so I'm questioning how they operate:
Are they on with ACC or on with engine running ??
Do they remain on with low beam headlights ?? High beam headlights ??
Are they on with parking lights ??
And can anyone suggest the appropriate circuit to tap into for proper operation ?? Preferably a circuit that's accessible in the engine compartment rather than the fuse box behind the glove box... Perhaps the center post of the isolator ??
As always - thank you for all of the experience and wisdom shared here.
Steve W
1973 23'
Southern California
Steve W
1973 : 23'
Southern California
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| Re: Questions about Daytime Running Lamps DRL [message #318255 is a reply to message #318254] |
Tue, 30 May 2017 23:23  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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With body computers on most modern vehicles these days, most DRLs are controlled by them. Some DRLs run the headlights a lower voltages. Others run separate lights. There are several other implementations. On my Colorado the DRLs are on only when the engine is running, the trans is not in park and maybe neutral, and the headlights are off. On my Blazer and Jimmy, the DRLs go off when the turn signals are used. Both vehicles turn off the DRLs when the headlights are on.
So you need to decide what you want to accomplish and figure out from there how to wire them. DRLs are normally lower wattage so heavy wire and planning for the electrical load is probably unnecessary.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Questions about Daytime Running Lamps DRL [message #318258 is a reply to message #318254] |
Wed, 31 May 2017 05:55 |
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RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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My coach has DRL from a PO, its been a legal requirement on all new cars here in Canada since the early 90's.
Its not LED just the regular OEM incandescent, but it might help you. A cube relay is mounted on the aluminum wiring plate under the passenger side hood.
-One side of the relay coil goes to the center of the isolator to provide power to the relay only when the engine is running.
-Other side of the relay coil goes to the power wire for the high-beam headlights. (this will provide the ground through the high-beam filament when the high-beam is off)
-Common relay pole goes to battery positive post on the aluminum plate.
-Normally open pole connects to the low beam headlight power wire.
Operation:
-When the engine is started, 12V from the alternator terminal of the isolator is applied to the relay coil. The low current of the relay coil goes to ground through the high-beam headlights filaments and pulls in the relay contacts. This now provides power to the low beam headlights for DRL.
-When you pull ON the headlights on low-beam, the relay contacts are simply in parallel with the headlight switch and the clearance and tail lights come ON.
-When you switch on the high-beams, 12V is applied to the high-beam power wire. This puts 12V on both sides of the relay coil therefore 0V across the coil so the relay contacts OPEN and the low-beams go OFF.
Hope this helps or gives you some ideas.
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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| Re: Questions about Daytime Running Lamps DRL [message #318259 is a reply to message #318254] |
Wed, 31 May 2017 07:42 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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As an aside -- those vehicles that use the main lamps for DRLs are the main cause of the lamps being burned out at night when you actually need them. Also they aren't $5 anymore like the old sealed beam where you got a fresh reflector and new real glass as well.
John Lebetski
Woodstock, IL
77 Eleganza II
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