Ok, there are 4 wires that connect to the starter. This thickest one goes to the battery. Then there are 2 red ones and a purple one. Are both red ones suposed to be hot at all times? How about the purple one? Only hot with key on? Does one of these wires suply power to the ECM?

 

The wires hooked to the same post as bat cable will be hot all the time. Purple appears to go to neutral safety switch according to the diagram below.
Corky

 

Yes, thick one goes straight to battery. Two smaller ones go on same post as battery so they are always hot. They supply power to the rest of your car.
The purple one goes by itself to smaller post. It is only hot when you want the starter to crank. It energizes the solinoid on the starter.