Random beeping/buzzing, please help.
 

Long story short I have an 88 rx7 that I got a couple years back and it has sat for quite some time because I have not had money or time to fix. Now I do and while I was attempting to get it started it sputtered a bit and almost started, but then decided not to. Shortly after that whenever I put the key in the ignition and turned it to acc. and left it for about 5-7 seconds, the car would start this steady beep/buzzing sound inside the car. I can not tell where it is coming from. Does anybody know what this sound is, what it could be, or what could have caused it? I have posted this on an rx7 forum as well.