I'm having issues heater/ac blower sometime works. when you start it might work if not after you have been driving it will start blowing. Also the cruise control. We started out on a 100 mile trip I set the cruise and it worked but on the way back it would not work. I just wonder if it might be a bad ground like G201. I do not know the location of this circuit. I replaced the resister and that did not help. thank you

 

It looks like the cruise controls and the blower have different grounding points. But, they do share the same circuit from the ignition switch. The ignition switch is a common problem on this generation of Impalas.

 

hammer fist the blower motor...if it starts working, you need a new blower motor.
if the cruise is faulty there will be body codes set in the bcm. check them. a code reader will not access body codes...you need a full function scan tool.

gm has a grid component system set up for the wiring harnesses. 200's are in the passenger compartment near the dash. g201 is under the dash to the right of the steering column.

 

What I did to fix the blower. I changed the ignition switch it now works fine. As for the cruise control it didn't fix I'll have to try research that problem. Thanks for the help. Al Gotch

 

I replaced the ignition switch now the blower motor works like it should. The cruise still no work I hod my nephew scan the car and there was no codes. Is there an easy to check the problem. Thank You Al

 

Check the brake switch on the brake pedal. If it's out of adjustment it could prevent the cruise from engaging. To test, try using your left foot to lift the brake pedal while engaging the cruise. Check the connector on the cruise control module: tight? clean? loose wires? corrosion?
Does the cruise light on the instrument panel light up when you start the cruise? If yes, check the throttle cable from the cruise control module.