Dic goes off when I turn A/C fan on.

[randy val]

Sometimes when I turn on the fan for heat or A/C the dic, daytime driving lights and fan all go off. When I turn fan back off dic and lights come back on. The next time I drive it all works fine. this is on a 2001 GTP.

 

[djwags]

Ive had a similar problem recently. It was fuel gauge, lights, and fan were not happy when i turned them on together...

 

[jmt455]

Fixed mine recently.
Exact same symptons: it was the ignition switch.
Replaced the switch and everything is now A-OK.

Here's how to confirm the diagnosis:
Sparky's Answers: 2002 Pontiac Grand Prix Blower Inoperative, Erratic

And here's how to replace the ignition switch:
Sparky's Answers: 2002 Pontiac Grand Prix, Changing The Ignition Switch