ignition switch harness or blower resistor

I have a 1997 gt.with 3.8. The head lights are dimming to almost off when the ac blower switch is turned on. The blower only blows on low in postions 123 and on high on 45. Dose this sound like blower resistor or ignition swith harness or both. If so dose anyone know the part numbers to both so I can order them through gmpartsdirect.
thanks
jason

If your blower motor resistor (BMR) goes out, setting 5 should only work.

Generally if the ignition switch harness is failing your lights should start "freaking out."

I wonder if there is power being drawn when the blower motor is operational causing the lights to dim.

Try these threads:

http://www.automotiveforums.com/vbulletin/showthread.php?t=261041&highlight=ignition+switch+harness

This one makes me think it's harness related

Here is the thread with the part numbers. Make sure they match your car first. If you want to double check, call a GM dealer and ask for a part number. They typically won't question it :).

http://www.automotiveforums.com/vbulletin/showthread.php?t=386768&highlight=ignition+switch+harness

Good luck. Both the resistor and harness tend to be an issue. However, since it's not just the fan, I am almost positive it's the harness. However, I am not an expert.

One thing you want to do before repacing any parts is to perform a little diagnosis.
Check the basics first..do you have a good battery and a good charging system?
If battery voltage drops, wierd things could happen .