78 300tdt srs question

I removed the passenger side kick panel while doing some carpet detailing and I notced a rectangular box with its corresponding 12 pin plug lying loose on th floor.
The dealer told me that this is the Voltage Transformer for the SRS, the purpose of which is to maintain power to the SRS system should there be a temporary power loss to the car. I don't know how or why it became unplugged, but I'm a little hesitant to just plug it in without a little knowledge about how it works. At $350.00 for a new one I'm sure it serves an important purpose. The SRS light on the instrument cluster works as it should, and I know that the airbag is plugged in at the steering wheel.
Can this transformer be tested? Will the airbag deploy with this unit unplugged? I ran a search but didn't see anything on the subject. wonder how many other cars are out there with this box unplugged.
As always, any help on this subject will be appreciated...
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continues to be the best source of good MB info on the net.
Thanks to all.