Driving Lights Wiring

[kramttocs]

Rusty and Jim's discussion in the alternator thread reminded me that I needed to improve my driving light situation.
I purposefully wired the dls to be on their own circuit so I could turn them on any time regardless of ignition or headlight switch.

But it only took one time driving at night to realize that meeting a car when popping over a hill and having to hit both the foot dimmer and the dl switch was a pain.

The switches I am using in my control panel aren't offered in a 3 way config.

How's the below look? Any improvements I can make on it? Goal is to let me manually control the dls but won't let them be on with the low beams.

[ArdWrknTrk]

This is similar to how I have my fog lights wired.
They start from 87a of the high beam relay and their relay gets pull in power from the parking light circuit.
The fog light switch makes ground.

So my fogs can be on any time the marker or low beams are on, but shut off when the high beam relay is energized.

[Gary Lewis]

I think that will work.  But let me map through it:

When the driving light switch is on the upper left relay will pick and provide power to the bottom relay's pin 30

If the low beams are on the bottom relay will be picked so the power goes to pin 87 and not to the driving lights

If the low beams are not on the bottom relay will not be picked and power goes out 87a to the driving lights

But, can't you do it with two relays?  Put power to pin 30 of the bottom relay and move the output to the driving lights to pin 87.  Then use the driving light switch to provide power to that relay's pin 85.  If the low beams are off then the relay's coil will see a very low resistance to ground and it will pick.  If the low beams are on then the relay's coil will have battery voltage on both sides and won't pick.

[kramttocs]

Only using two would be great. I never think of using anything but a direct ground.
So this?

[Gary Lewis]

Yes, that's what I was thinking.

And I like the little arrow on the relay showing that it is in the quiescent state and that when energized it'll swing to the other position.  Too many diagrams leave you guessing.

[ArdWrknTrk]

That should work!  

[kramttocs]

I used https://www.circuitlab.com/ for that one. Just found it this morning. Had to sign up and it looks like you have to have a membership to save but for quick throwaway designs it's definitely one of the nicer ones I've found.

Thanks a lot guys! That really simplifies it and saves a relay to boot.

[ArdWrknTrk]

I don't like seeing it as a swing switch, like a door, but Scott's relays are better than the ones I mentioned the other day.