When I start the car sometimes everything will work. Other times the windows, speedometer, tach, temp, blinkers and a/c will not work. At times everything will work until I shift into drive then everything stops again. At times while I am driving along everything will come back on and work. Other times everything will be working until I try to use the blinker then everything goes off again. It only affects the blinkers, windows, speedometer, tach, temp, a/c. I have checked all of the fuses, all good. The flashers work ok. Is there something that connects this group together? A relay or a switch?