Can anyone identify this beeping?

[gorp00]

I'm rebuilding my 97 XLT after a front end accident. I have the instrument cluster and the airbags out. Over time the battery went dead. Now, after a charge, when I start the engine I get a beep from the passenger dash/firewall area. It's a series of 3 beeps for about 20 seconds. Not the ignition sound but an electronic beep. Never heard it before. Anyone knows what it means?

 

[Collin Whitfield]

I would bet that that is the Restraint control module (airbag controller) which beeps when it senses the airbag indicator light is burnt out, or in this case entirely absent as the instrument cluster is out.

Once you put the cluster back it it shouldn't beep anymore.