97 Deville northstar blower motor? And CAM sensor?

Hi' I got a 97 deville and the blower motor [heat] wont go on, there are 3 wiresgoing to it red, grey blk the red is gettin 12volts blk is grounded but the grey is supposed to be fan speed control. No power is going to it I would assume it should send signal to turn on? Then I powered the blower with my own jumpers after unhooking the plug 12v to red terminal on motor gnd to blk and power to grey and nothing a new 1 is like 250 and seems weird that there are 2 problems am I missing somthing? Then I got a code po340 on my scanner so I checked connections looked ok I changed sensor and still comes back but if I clear codes and hold rpm above 1600 it will not set until idle any help would be app. Thanks