Welcome to the Site. If you are able to post a picture that would help us identify the make and model of the machine.
Typically on the either side of the machine there is an identification tag. Also somewhere on the main door on the bottom right corners there is a logo indicating the make. If you aren't able to find it there you may check the main base that the compressor sits on.
For free vend switch check with MoonDawg or JohnieG. Hopefully they will chime in.
Here is link from the site for free vend. It's under the Coin Mechanism section
http://soda-machines.com/discussions/index.php/topic,871.0.htmlAs far as the light depending on the model you may check for a florescent starter. Is a small round piece.
Jared