First off what carb are you running??
Though on pretty much any carb the electric choke works pretty much the same.
The power wire must be connected to a switch power source, when the key is off it has no power to it, when you start the truck power goes to the electric choke.
Inside the black plasic cap on the right side of the carb there is a metal spring.
When the truck is cold, and no power is going to the spring the spring is relaxed, which makes the choke close, reducing the amount of air going into the carb and making it run richer.
When you get into your truck, you pump the gas pedal 2-3 times it activated the high speed idle cam on the right side of the carb. Sincee the engine is cold, and no power has been going to the spring in the choke, the choke is now closed. So when you start the truck, it is running richer, and the cam for the high speed idle is activated.
As power goes into the spring, it slowlly tightens up and as it does it it pulls the choke open. As it opens the extra rich condition of the choke being closed slowlly goes away, and the high speed cam relases. A fuel injection system does the same thing but all electroniclly.
If you have the wire from the choke going to a constant power source, like direct to the battery it will never close, and thus never make the engine run rich when you start her up cold.
So here is what to look for
Take your air cleaner off, pump the gas pedal two times. Go look at the carb, and make sure the choke is closed. If so then start it up, and watch the choke plate. It should slowlly open up as the power goes to the spring. After a few minutes it should fully open.
By loosening the 3 screws on the side of the black plastic cover for the spring you can adjust how quicklly the choke opens. In the summer you can let it open faster, in the winter adjust it so it opens slower
