a/c blower switching on and off

[mariner98]

I have a 01 and it is having some hvac issues. I have seen many mixed threads on this but maybe I can get some issues more directed at my exact problem When I turn on the car the blower (most of the time) won't come on until the care is warmed up (15-20 minutes) and then it will sometimes but not always shut itself off after anywhere from 20-30 minutes. Only to go through the whole cycle again. The air blows ice cold and the heat is nice and hot it is just the blower. The only other thing that has gone wrong on the same system panel is that the rear defogger strips would not turn on but that only happened once so I don't know if it has anything to do with this. Any help would be great. It is hot out and this is starting to hurt.
Jon

[jmt455]

Sounds very similar to what mine did...I recommend you start with the diagnosis procedure for the ignition switch.
Use the links in this thread:
http://www.grandprixforums.net/dic-g...fan-48155.html

[jmt455]

Here is the text from one of my earlier posts that includes the links for the ignition switch diagnosis and replacement:

I recently fixed these same issues on my '02 GTP.
My HVAC controls, DRL, DIC, HUD all were acting flaky.

The ignition switch had to be replaced.

I tried the bypass first, hoping to save the cost and effort of replacing the switch assembly, but the bypass only worked for a few start cycles. The ignition switch contacts were badly scorched/burned.

Use this diagnostic process to verify that it is the switch: Sparky's Answers: 2002 Pontiac Grand Prix Blower Inoperative, Erratic When I checked mine, I found 0 volts at the HVAC/DIC fuse.

Excellent write-up on switch replacement procedure here:Sparky's Answers: 2002 Pontiac Grand Prix, Changing The Ignition Switch

The best, bullet-proof solution would be to replace the switch AND install the bypass with the new switch. If you do this, the new switch will never see the high current loads and it should last indefinitely.

Switches are available from any auto supply. I actually got the best price on a Delco unit. Good luck!
Joe

[mariner98]

Thanks to all the info coming in. I will try the ignition switch testing and let everybody know how it turns out.
jon