Thank you that is confirming my suspicion, I am interested in doing the 'factory authorized' service work more than the sales / install volume. I realize allot of the service work is not 'electrician' type work and that is where my semi-retired mechanic friend would fit in.
You're not going to get much service work if you're not selling them. I can tell you with Generac its a ranked system when customers call into the 800 number. Its you, versus the guy with every single part needed in his warehouse. My buddy that is big into Generac has thousands of parts on hand, a couple dozen service techs, orders generators 200 at a time, covers three states, etc.. etc... That's the sort of dealer you're likely competing against when someone calls the manufacturer. You need to build your own service customer base through sales. Not trying to talk you out of it but I am giving you the best advice I can based on my experience.
As for cost out of pocket, you can do it for $1k. The online classes to get started are free. The in-person classes are about $500/ea; you need to do liquid cooled and air-cooled. Since covid, Generac has been traveling around the US doing them instead of requiring everyone to fly to Wisconsin. You have to attend the in-person training to buy parts and get phone tech support.
This applies to Generac only, but the next big push from them is "clean energy"... They are making a big push into battery backup power, and they want their dealers to attend this training and get certified. So that's another area you'll need to become proficient in to be a preferred dealer.