My '01 Monte Carlo has been sitting for a number of weeks. Today I went out to remove my driver side door panel to replace my speaker. I then disconnected the positive battery cable and replaced the speaker.

Got done and hooked up my positive cable and the car is acting very strange. The gauges are surging and making a sound from the dash. Basically nothing electronic works. Scared my bcm is fried..... I made a video but can't get it uploaded?

 

Did you only remove the positive? Because it's the Negative that you need to remove when you do work.

The battery could also be dead for sitting so long, have you tested it?

 

I removed the positive. Car has been sitting outside for a month un-used but the battery was replaced in November before it was parked.

 

https://www.facebook.com/100010092314905/videos/204008579945551/

 

https://www.facebook.com/100010092314905/videos/204008579945551/ Link to video

 

Dead battery... Jumped it with my truck and all electronics came back... I honestly didn't think a brand new interstate battery would go dead after just one month of sitting.

 

Make sure you disconnect the negative first. Don't ever just do the positive.

And if the car will sit longer than 2 weeks, I would get a trickle charger on it.

 

Mine is doing the exact same thing. But tried jumping it and it didn't help at all.