Blazer beeps at startup
 

Whenever I startup the blazer there is a loud strange beep. it is totally different than any other sound the blazer makes. it's not the seatbelt, keys, lights none of those types of beeps. It lasts about a minute, and no issues drivin.

Tried narrowing down where it's coming from? Under the dash I'm assuming, but like the driver's side or passenger side?

Possibly some aftermarket security system or maybe from an aftermarket radio?

It is comin from under the dash near center. Stock radio and alarm.

I had that on my Tahoe turns out it was oil pressure sending unit? Then the Tahoe spilled all the oil out and had a small oil fire on the highway