Hello again!

Long story short. It took me only first five minutes under the car to get frustrated!

So, tracing the wires clarified me that my cooling fans system was completely modified compared to the stock one. Someone decided that he doesn't trust the GM way to cool the engine. So for now cooling fans system is completely separated from the ECT sensor in the water pump and the PCM. It works like... ...just look at the my diagram...

http://www.mediafire.com/file/gq2tyv...ns_Diagram.jpg

After the discovery I took that relay for test. And if I connect 12 volts to the relay it works well - starts clicking. I assumed that if relay is healthy than the issue is in that custom ECT, that is installed in the hose that goes from thermostat to the radiator. I don't know why it is failed. But there is an easy way to go, just replace it while replacing a water pump, when all of the coolant will be drained.

But I will try to find a way to return to the stock fan system setup, when three rerkay system is used and both fans operate low and high speed togetger.Thus I need to test all the wiring between PCM, fuse box and fans.Diagrams and images of stock wiring of the fans system will be the best.
Thank you very much!!!