Drl's How It Works?

[jeebowhite]

OK, so the subject may seem a tad obvious...

Basically I am looking at installing DRL's, and whilst I would LOVE the type that Lenny and Pree have on their cars, I couldnt afford that, but I found some E rated sets on eBay.

Judging by a youtube video I just watched (created by Ring Automotive) it states that in essence you need to play with three wires...

1) connect the negative lead to the negative terminal on the battery
2) connect the positive lead to the positive terminal on the battery
3) connect the switch to the headlight wire

All sounds relatively easy? I dont doubt that... But I have a burning question and I cannot bleeding well answer it...

if wire 3) above is used to switch OFF the DRL when the headlights come ON... Why are the DRL's not permenantly on...

for example, its connected to the positive and negative of the battery... this is NOT switched by itself, its now connected to a permenantly live source. so why do the lights not remain on? technically, when your cars off, so too are the lights, and therefore the lights being off are technically the switch for the DRL's are ON....

so why is it that in the video I watched, the DRL's switch off with the car - am I missing the basics here :P its been a very long day!!!

[trikidy]

I would hazard a guess that the connection to the side light is the reason, rather than being a complete circuit and being on, the connection to the sidelight bit must complete the circuit when on and off when off- thats a guess!

[jeebowhite]

I kinda thought that, but then the lights are off when the cars off, and when the lights are in the off position... lol, thats why I cant quite make sense of it...

[trikidy]

Think I have it. He mentions connecting to the positive wire of the side lights, this must be the wire that usually turns the sidelights on.

So when you think of side lights the circuit is complete under the bonnet, but a switch has been installed (the controls to turn them off and on), as the wire is connected straight to the positive it must 'avoid' the loop that has the switch attached.

Because in theory the sidelights are on when the engine is on, but they are not producing light until you turn the switch on, as the DRLs are avoiding the switch it must just be on when on and off when off.

Sidelights also turn off when the main beams are on, this must be some kind of circuit that cuts out the sidelights when the switch is for full beam. This would support my idea!

Any help?

[jeebowhite]

that seems to be a bit more logical than I could think of it :) it just wouldnt click! haha...

Now which ones right... OFF or Dimmed... I see many cars out there that appear to have OEM lights that dip when headlights are turned on. and also a lot of the rules I have seen on websites show that lights must be switched OFF as soon as sidelights are switched on... is it therefore illegal to dim the lights down, as opposed to OFF?

For example, the directive that rights these rules and enforces them says:

which refers to "headlamps" (I would describe those as dipped headlights?) but it doesnt refer to sidelights?

http://www.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/r48r6e.pdf

6.19.7.1

[trikidy]

I think it refers to sidelights, I would imagine that your sidelights will not work while these are connected as they have taken the positive cable bit so there will be no input to the sidelights.

"are not switched ON when the daytime running lamps are switched ON"

I think that is just bad english to say the sidelights will not switch on while the running lamps are connected (which they refer to as on)

"lights must be switched OFF as soon as sidelights are switched on"

Like I say, I think it is more to do with how they are wired rather than legally, because these are effectively taking the wiring from the sidelights I don't think the sidelights will be connected.

Could be wrong but it's just what I think mate!

[jeebowhite]

agreed, I just see that the problem with this is interpretation, and the rules arent overly clear to prevent mis interpretation! will be good to see what others thoughts are!