2003 headlight/ac problems

I have a 2003 pontiac grand prix. The a/c only works on high. I have replaced the resistor but it still only works on high. The headlights if they are on automatic will not come on either. If you turn the ignition switch on but dont crank up the car the ac works in all 5 speeds, if you then crank up the car it only works on high and you have to wait for it to come on. If you move the headlight swith to the on position instead of auto the ac comes on after only a short delay? I have taken it to a shop and their suggestion was a resitior but that did not fix the problem. Anyone have an ideas.

Sound like your ignition switch is bad?

I'm having the same exact symptoms. I ordered a new ignition switch, as soon as it was delivered, the symptoms disappeared. Oh well it's just a matter of time before it acts up again. As soon as it does, I'll switch it out.

I would agree that you need a new ignition switch/harness as well. Your symptoms are classic for an ignition switch issue.