Ok i have a 2006 Grand Prix i just bought it and when i bought it i was told it had a bad heater core which it indeed was bad/ leaking. So i changed it and had heat for one ride in the car after that and then there was no heat just slightly warm air. I replace the thermostat after and bled the coolant system but still no heat. I took it to get the codes read/cleared and as i was driving it back to the house i hit a bump and i had heat blowing until i got home and put it in park. Again i have had no heat since. My opinion is that
A. I have a loose wire somewhere.
B. I have a bad solenoid somewhere. (But as this is my first Grand Prix and my first front wheel drive car i don't know much.)
C. One of my motors are shorting out.
If anyone on here has run into something like this and could give me some pointers it would be much appreciated.