99 Astro - Airbag light on

I just received a 99 Chevy Astro with 89K miles. The previous owner said that they had the engine steamed cleaned and afterwards the Airbag light lit up on the dash console. Also, after driving the car several miles there is burning smell coming from the engine compartment. I suspect a short after the engine cleaning was done.
Can anyone tell where I should start checking to isolate where the smell is coming from? I'd like to localize the problem first before taking it to a dealer to check on the airbag light.

Thanks,
Chris