stanz

iTrader: (1)

I just installed a flashing LED light in my dash to simulate an alarm. It was a simple three wire hook up: constant 12v, ground, switched power (works as floating ground when ignition off).

The LED works great when the ignition is off. It promptly goes out when the car is started and running.

The only quirk is that whenever I run any momentary accessory (rolling a window up, turn signal, wipers, etc,), the light begins blinking again under that additional load. It sounds minor, however, the LED is super bright and in my line of vision.

Any suggestions on how to resolve this?

It's funny how bright it is. When my car is parked on the road at night cars slow down when they approach it. The flashing blue light looks almost like an undercover a police light.

wyoming9

iTrader: (1)

What Circuit did you use for the switched power??

I would guess the load on the systems appears to your light as if the key is turned off.

Turning your light on.

You might have to upgrade your electrical system if you see a massive voltage drop.Install a bigger battery to make up for your alternator short comings.

I was thinking install a capacitor but then your light would not turn on till it discharged.

Not knowing how sensitive this light is I am only guessing but would guess it goes off as soon as your voltage is back to where it should be.

It is possible what you got is defective only you can know that.

scope103

You haven't told us much. I assume your light is a commercial unit with electronics which senses the voltage on the switched power line, and turns the light on when the switched voltage is less than (how much less than?) the 12v line. You also haven't told us where you found the "switched" 12v line.

It could be that your unit is just a little sensitive, and it's picking up the 1v voltage drop when the window motors run. Or you might have hooked it to a wrong wire. Before you start replacing batteries you could stick a voltmeter on the "switched" line and see what it says when you run the window.

stanz

iTrader: (1)

Thanks for the quick replies. Yes, this is a commercial set up (from amazon.com) and I hooked the floating ground line to the cigarette lighter. Since it's LED, the light only requires a few volts to run. It was super bright when I tested it with a 9v battery.

I'm 1000% positive I wired it correctly.

My charging system has a new alternator, Optima battery and big 3 mod. None of my other lights even blip when operating these other accessories.

I'm thinking that it's just that sensitive. I'm also positive that it's not defective.

Perhaps a relay on the floating ground wire would do the trick? I don't want to throw a lot of money at a silly little light.