crangip

Hello,
The brake warning light on the dashboard of my 1991 300 SL went on yesterday on my way home along with the light was a beeping sound that would stop when the car stopped moving and started once again when it started to move.
I just had my front rotors and brake pads replaced in late Dec. 2012 and the mechanic checked the rear rotors and pads at the same time. Other than the rear rotors/pads what else could be causing the warning light and beeping? I asked a Porche mechanic I know what the problem might be and he asked me how strong the battery was that sometimes when the battery is weak a warning light will go on and a beeping sound will begin. Can anyone help me with this question?
Thank you very much,
Crangip

SRHsl600

Fluid level, fluid level sensor, Brake, emergency system "on", as in the peddle has been pushed slightly, but not far enough to add resistance. I'm sure others are also possible from the work done with the brake.
Have fun hunting!