SRS Warning Light: 1994 S Class sedan

[bluhorizan]

Hi:
I just purchased a used 1994 S Class sedan in great condition with 118K miles. I noticed that the SRS warning light comes on with start up and then stays lite for about 2 minutes and then goes off. The owners manual says it should come on and then turn off within 4 seconds. The seller tells me that the SRS light has been staying on for about 1 minute or so for the past year. I also noticed that the seatbelt red light is lite up for maybe 30 seconds despite being buckled in. What does the SRS light staying on as described signify? airbags? seatbelt electrical connection?

Do the airbags need to be recertified or recharged on a certain schedule? If so, how expensive would this be?

Thanks for everyone's advice on this.