I think that's a good idea.
If you want to be more productive, help bring in new business and keep it there. Understand that's not your current job, so you need to talk to your employer and discuss these ideas with him before doing any of this on the clock.
Start categorizing all of your contacts/customers to make it easy to start a good marketing and customer satisfaction program.
I agree with the others who said try and learn the lingo, and learn the names and locations of parts. When a tech calls in and needs to know if something's on the shelf, you can quickly look if the shop manager is busy with something else, thus limiting the amount of time your electrician is on the phone with you instead of working.
The fact that you're interested in all of this should comfort your boss in knowing he's got a good employee, even if he doesn't want you doing anything besides what you're doing now.