over heating

I have a over heating problem and it is electrical the fans ,fuses, relays are good checked all these parts low coolant light on dash flashes. fans do not come on at the temp , when a/c is turn on they work fine.

for the future, you'll get a much more helpful response if you leave year, model, mileage, and engine type.

depending on the mileage, you may want to have your t-stat checked (or just replace it for the 10 bucks it will cost) and make sure that the coolant level is where it should be (especially since the low coolant light is flashing!!), and look into getting the coolant changed if it hasnt been already.
green coolant should be changed every 30,000 at most (better to do it once a year, it only costs about $60) and orange coolant, even though GM says it will last 5 years/150,000 miles, dont wait this long unless you want a huuuge headache.
theyve had problems with this coolant gumming up and clogging coolant passages. so check the t-stat and coolant first, then start checking fuses, relays, etc

You should check the engine temp sensor. If it is not working properly it would not start up the fans when it is supposed to. The fans should start if the engine temp reaches 210 degf. If the engine reaches 210 degf and the fans do not start then the engine temp sensor is bad.