My goal, keep a wire from putting out any voltage until it sees 12 volts.

So this wire I'm messing with is putting out 4.5 volts.  I want to use a resistor to drop the voltage low enough, that it will not switch over the 5 pin relay.  When you turn the switch this wire is connected to, the voltage goes from 4.5 volts to 12 volts.

My theory is that I can drop the voltage using a resistor, so low that it wont energize the relay, and the relay will stay closed, but when the voltage jumps from 4.5 to 12 volts after turning the switch, the extra voltage will then trigger the relay, and direct voltage from the battery source will then flow out. 

Basically I dont want to see 4.5 volts ever, either 0 or 12.  I'm sure some of you know what I'm doing.  Please let me know your thoughts, and if its possible, what resistor I'd need to drop 4.5 low enough to not trigger the relay, but high enough that with the extra 7.5+ volts passing through with the switch turned WILL trigger the relay.

I know these 40 amp relays need very little voltage to trigger, but other than that, I have no clue about ohms or any of that.  Thanks so much ahead!

Chris

4.5 volts will not energize a Tyco relay, but it may be enough voltage to keep it energized when the voltage drops from 12 down to 4.5

LOL, I felt like such a dork after posting this.  I didn't even think of how easy it is to test all of this theory.  I grabbed a 9 volt battery and hooked up a relay and was able to get it to energize.  Then I tried a 1.5v AA battery, nothing, added another AA, nothing, then tried another at 4.5v, again nothing.  Even 4 AA batteries at 6v didn't do anything more than create a very faint reaction, but didn't energize the relay.

I just did a test, and the relay on its own worked perfect!?

So long story short, I just posted before testing on a Lexus IS350.  Apparently everyone who wants to get rid of the ugly faint yellow glow coming from the high beam section (high beam bulbs running at 4.5v), has been told they need to go visit a dealer to reprogram the cars computer to disable the function.  Problem is, most dealers are morons or crooks, and very few are willing to work with the automotive enthusiast, especially not without some hefty costs in doing so. 

I'm working on the 4th IS right now, and I told the owner yesterday he'd have to go ask a dealer to turn of his sons DTRL function via their special hardware tool.  After I called him I just felt like nobody has really tried to tackle this thing.  Now I'm realizing that nobody facing the DTRL issue has made much effort to tell everyone how easy it is?

I opened the fuse box, followed the high beam wire to its source and about 6 inches up I cut the wire.  Meanwhile I had a relay (30 & 85) hooked up to the battery power and ground.  I put the wire putting out the 4.5 volts into my trigger (86) and the other end of the high beam wire, the one feeding the actual bulb, hooked up to 87.

Worked perfect.  When 4.5v was being putting out the relay was not switching, but when the full blast of 12v came into the trigger, the relay switched, giving a direct 12v from the battery (or 13.8ish really) to the high beam bulbs.  If you bothered reading up to this point, my question is, what advice can you give me for long term durability of this setup? 

 I'm sure I could tap into another cricuit for the power and ground for 30 and 85, but with the draw of a single 55w high beam halogen bulb, I'd feel more comfy with a 18awg fused connection to the battery directly.  Then an HID kit could even be swapped in there later and it'd work perfect. I think this method will work for every single car out there with Day Time Running Lights built in that power up the high beam bulbs at low voltage and look terrible.  I'm not just trying to remove the DTRL function, but rather enhance it.  Check out the video I posted last night showing the lights I added instead of the stupid dim high beam bulb :)

http://youtu.be/Nmup9fBGmC8