97 Grand Prix - Blower Motor, Temp Gauge, Running Lights, rear defroster Problem

[jamesggray]

Hello All,
I have a 1997 Grand Prix SE with a 3.1 L - 104K miles and wierd electrical problems.

First the Blower Motor will work sometimes on the 2,3,4 settings, always works on 5. When I switch the blower off the running lights come on and the rear defroster works.
When the switch is not working on the 2,3,4 settings, the daytime running lights do not come on, and the rear defroster will not work. Then out of nowhere the lights come on and the blower will start working, and the rear defroster will work.

Also, when the car is at idle, the heater will go from blowing hot air to cold air, and the temperature gauge will start climbing. When the rpms increase, either driving or revving the engine the gauge will drop back to normal and the hot air will start blowing again.

All help is appreciated.
Thanks,
James

[richtazz]

The blower motor/defroster/lighting problem is probably a bad ignition switch. If it was just a blower speed problem , I'd say it's a blower resistor. The cooling system issue is a classic symptom of an intake leak, subsequently allowing air into the cooling system, and the anomolies you describe.