Printer Friendly Forum Posts - DRL Cutoff Switch

Hello, I have been trying to find an answer for ages and no matter what I search I cannot seem to find an answer. Hoping someone can help me out. I have done a lot of reading and am at least somewhat familiar with automotive wiring, enough not to screw thing up too bad. Most of the time.

I have an older Jeep Wrangler. When I bought it it already had LED Daytime Running Lights added that are on their own harness spliced into a wire that is hot when the ignition turns on. It works great, turn on the car, DRLs come on, turn off the car DRLs turn off. The problem is that I work late and when I come home my lights shine in the kids window when I turn in the driveway and my wife gets mad at me for waking him up. I can kill the headlights but not the DRLs. I like having the DRLs I do thing they help somewhat, I feel like cars turn out in front of me when they shouldn't less frequently than on my last Jeep. Could be just placebo effect.

So what I want is a switch to turn them off, easy enough. I have installed Carling V series switches for other lights where the bottom is independently lit and the top is dependently lit. Ideally I want my new switch to match, because I am picky like that. Since the switch will be on 99% of the time I really don't want the dependent light on all the time, and it would also be nice to have a light to remind me if I forgot and left them off. So what I want is basically the opposite of a normal switch that lights when on, I want it to light when off. I have no experience with normally closed relay or using the 87a terminal on and SPDT relay but I was thinking that might be the key to my solution. I wish I had a test bench where I could test it out but I don't think I would get enough use of it to justify spending the money.

My first thought was to use an SPDT relay and run the battery to 30, the on/off switch to 86 ground to 85 and 87a to the lights, but I think the DRLs would be on even with the car off, but I could be wrong. So to solve that problem I was wondering if it would be ok to connect 30 to an ignition switched wire instead of straight to the battery. This essentially means that 30 and 86 will be fed from switched ignition sources since the on/of switch in also connected to a switched ignition source.

Is that OK to do? I don't know enough to know if there is a reason not to do that. And would it really accomplish what I think it will? When the switch is in the On position the dependent light on the switch will illuminate but the DRLs will be off and when the switch is in the off position the dependent light on the switch will be dark but the DRLs would be on?

I know I am creating a overly difficult problem that really isn't necessary, but things that don't work the way I think they should drive me nuts.

Thanks
DW