Have 2001 Monte SS and its driving me crazy! The door lock on the passenger side keeps trying to lock over and over and won't stop gesill keeps going. Thinking it must be in the auto door lock system? Never had a key fob since I had it so that's ruled out. Also the other problem is the charging system. When you start it starts charging on the guage and all other gauges work. Then a short time something sounds like it clicks in the dash and all gauges including the charge guage go to zero like you shut the key off then immediately they all go back to normal except the charge guage which stays at zero! I replaced the alternator and have the same problem. This is my first monte and really like it but this is weird. Thanks for any help or suggestions.

 

This may not help but if you look up the steps to programming thru the radio perhaps you can disable the auto locking feature.

As to the dash, I hear several gm dashes go out. I had to have a new one put in my 03 suburban because the gauges all did that. Was $180. Maybe that's your issue but definitely something electrical.

 

Just a suggestion :

Check the body ground. It's the cable from the battery negative, splitting in 2, with one connection in the body juste under the battery.

Mine was all corroded and caused all kinds of weird symptoms including gauges working/not working. Since I cleaned it and greased it with Dielectric Grease, the symptoms desappeared.

May not be your problem, but costs nothing to check.