I have a 2002 Monte Carlo SS with a intermittent problem. Hard to explain but sometimes the dual climate controls will not operate also at same time the cruise will not function also the overhead driver information center is blank (not lit up). Then as you drive for a while the D I C lights up and everything starts to function properly

 

I have the same problem with my '03's odometer and gear position indicator. I suspect a poor ground for that circuit but haven't chased it down to confirm it. I wouldn't know where to start looking.

 

and I just found this thread. click on the link below.

https://montecarloforum.com/forum/mo...ay-unit-50935/

 

Had same issue, new ignition switch and all is perfect

 

Have the same issue. Actually asked about it on here too lol. Luckily the ignition switch just got recalled. I'm holding off until my appointment for the replacement which is coming up in about a week. Hopefully that'll fix the problem.

You should check if yours got recalled.

 

that recall just puts inserts in the actual ignition switch key. they dont replace the actual ignition switch inside the dash... just fyi

 

Damn that's beat. Mine seems to work if I start the car with the **** on three. I don't know why.

 

there must be a ground or something that runs thru the iginition switch. Im by far a wiring guru. I took mine out and the a couple of the spades where the terminals connect were sort of grungy. but i already had a new switch and replaced it.
Its not a hard project, takes about 15 minutes if you know how to get at it. I would say an hour if someone isnt so mechanically inclined.
There a post on youtube someone posted that pretty much exactly how to change it out.

all i can say 100% certainty is my car would most the time be just fine and normal. Then every so often Id start it up, notice the cruise light illuminated on the cluster, the overhead info inop, and blower controls no work. cut car off and on a few times and all was normal again.
After i changed the ignition switch ive had absolutely 0 issues and all works as should