Driving Lights vs Headlights - Difference?

[GMCTRUCKS]

My dad told me years ago that the voltage is dropped a bit I don’t know where he got it from but he does read a lot even at his age 91 years young.

 

[XJPhoenix]

Just to add in another observation, my folks and I have owned two GMC Yukons; a 1996 and 1997, both with DRL and both had ni visible difference between modes. I will say that both trucks seemed to have miserable output from the stock lights, rough driving in the country late at night.

HTH!

 

[Jeff7]

On my 1999 they are different brightness.

I usually use the DRL at night, unless I am on a non lighted roadway etc.

Not a huge difference, enough to notice though.

Dude that's not very safe, your tail lights aren't on with the DRLs, if it's dark enough (or poor visibility due to snow/rain/fog) that you want DRLs on then you should be turning your full headlights on so people behind you can see you. Even on lighted roads. I mean, what's the loss of being more visible?

 

[Ken K]

For years, ACDelco sold a rather expensive DRL module that had park brake apply cancel option and other features. The module controlled the low beams as posted above, but it uses a simple PWM at 50% of battery available. A 556 IC timer was used in "Astable Mode" to create a true square wave or on-off that is still faster than the human eye. It's circuitry, controlled two "P-type MOSFET's" to produce 6 to 7.2 volt DC to operated the low beams. The benefit is bulb life is extended by twice as compared to full voltage on continuously. Most headlights pull about 4 amps, and bulbs are cheap for the most point. I just like the idea of DRL to help me being seen in all weather conditions.
Sorry about getting to geeky, but I taught 6 electrical classes for Delco and retired after 30+ years of being an ASE Master Tech. Just run a switchable relay to control you low beams and be safe.

For those of use who ride big bikes, most all states limit you to three lights. Ok. But if I point one toward the right curb at eye ball height and the rest on high beam all of the time, I will explained to the officer, I have a loose mount and see if that gets me out of a ticket. As do loud pipes save lives, being seen is the main issue. Air horns, not included.
I tell others, they could drive faster if they put down the cell phone.

 

[df2x4]

For years, ACDelco sold a rather expensive DRL module that had park brake apply cancel option and other features. The module controlled the low beams as posted above, but it uses a simple PWM at 50% of battery available. A 556 IC timer was used in "Astable Mode" to create a true square wave or on-off that is still faster than the human eye. It's circuitry, controlled two "P-type MOSFET's" to produce 6 to 7.2 volt DC to operated the low beams. The benefit is bulb life is extended by twice as compared to full voltage on continuously. Most headlights pull about 4 amps, and bulbs are cheap for the most point. I just like the idea of DRL to help me being seen in all weather conditions.
Sorry about getting to geeky, but I taught 6 electrical classes for Delco and retired after 30+ years of being an ASE Master Tech. Just run a switchable relay to control you low beams and be safe.

For those of use who ride big bikes, most all states limit you to three lights. Ok. But if I point one toward the right curb at eye ball height and the rest on high beam all of the time, I will explained to the officer, I have a loose mount and see if that gets me out of a ticket. As do loud pipes save lives, being seen is the main issue. Air horns, not included.
I tell others, they could drive faster if they put down the cell phone.

Was this DRL module ever standard on these trucks? Or just a part that they had available?

Thanks for the info by the way, very interesting. I figured if they did do something like this it was probably PWM based.

 

[mattillac]

Dude that's not very safe, your tail lights aren't on with the DRLs, if it's dark enough (or poor visibility due to snow/rain/fog) that you want DRLs on then you should be turning your full headlights on so people behind you can see you. Even on lighted roads. I mean, what's the loss of being more visible?

Thanks for you concern.

Guess I should have said:

I usually use the DRL at night(along with the park lamps/running lights), unless I am on a non lighted roadway etc.

Peace.