Strange beeping

My 90 wagon developed a strange new trick this week. Now, in addition to the seat belt warning beep, I have a second beeping whenever I turn the car on. Very strange and I have no idea why.
I know it's not the seat belt because they beep on different intervals - like the seat belt is on 1s, off 1s and the new beep is on 1s, off 1.3s. Two distinct patterns.
Anyway, anybody else ever have this happen?
I know it's not the seat belt because they beep on different intervals - like the seat belt is on 1s, off 1s and the new beep is on 1s, off 1.3s. Two distinct patterns.
Anyway, anybody else ever have this happen?
Comments
Also, it's coming from the area around the fuse box whereas the normal beeping comes from under the radio.
It never lasts longer than the seat belt. I wonder if there is a seperate automatic seat belt beeper?
I'll reseat the plugs under the seats and see what happens.