MelTay85

I purchased from an individual a 2001 GMC Sierra 1500 SLT that had a rebuilt transmission, placed in 2-3 week prior to our purchase. Was not a very wise choice to say the least, but that could have alot to do with it being a low rider. First problem was when we placed it in park, the dash said it was in neutral. Week went by and we had an oil change and in the report they said it had an engine oil leak, no problem as of that time. A week later was driving and it decided that it did not want to change gears. (This is an automatic). Could someone tell me the percentage rate of it possibly being wires coming loose?
Next question, I had came to believe the battery was extremely low on juice, the windows would not roll back up and then it died and would not start again. Each time I turned the key to the off position the security alarm would go off, so I had my husband unplug the battery. Each time when we attempted to plug the battery back in, the security alarm would start sounding again so now I am definitely stuck with rolled down windows and bad weather. Is there any possible way of disarming the security theft system so that we can get a battery in so that we can roll up my windows without the alarm sounding and annoying my household and neighbors?