I'm trying to wire a ground output from my alarm (.8 sec, 10 sec, or 30 sec) to make my windows go down. I have already wired the relays in the door, so I can hit the wire (that I ran to the cabin) to ground and the window goes down.
I've been trying to use this circuit from the12volt.com
Only instead of constant fused +12v and momentary 12v output, I'm using ground on pins 87 and 30.
With the 1K uF cap, it's supposed to put out 1/2 sec. output, but I need 3 sec. for my windows so I am using 5.9K uF worth of caps, but I still get only about half a second. Anyone have any experience with this? Is it not a linear increase for time vs. capacity? Is there an easier way?