it is the coolest tractor ever.. perfect size for my place. the serial number is A0106, so i figure i'm the 106th kid on the block to get one... i just finished putting the rear work lights on.. so now i need the proper connectors (the wire is there with the female connectors).. and i need a proper rocker switch for the dashboard. I had to drill the holes in the brackets for the lights.
If it's anything like the B2620/2920, there are leads already run to the rear right fender for the work light circuit, which are switched on when the ignition is on. You can wire a switch inline to the light from those leads. On the B2620/2920, there is a blank panel on the fender that is a perfect place for switches.
I haven't looked yet.. but i'm thinking if the tractor is already wired for the rear work lights, then surely it will be wired at the dashboard for the switch.
Congratulations! The B2650 is an awesome tractor. (I have a B3350 on order as we speak.)
As for the wiring, yes, I believe the tractor already has the all the wiring pre-installed for the rear work lights based on what I saw in the parts diagram. You should only need to order the switch (p/n: TD350-75360).
Behind the dash, at least on the B3350 . . . the B2650 should be the same, the plug and wire for rear work light switch is secured with blue tape to an upper portion of the wiring harness. It is not reachable without partially removing the dash so as to remove the tape and bring the plug down.
To remove dash, remove one Phillips head screw under the center package cubby. Then loosen two 10 mm hex head bolts one each side under the bottom lip of dash. Lift steering wheel rubber boot and then pull dash outer section up and to the right.
Here's a picture of my rear work light install, they are 36 watt LED's ($57 eBay) and provide much better light than the stock front work lights. Note that the "lollypop" light brackets on the "larma's" B2650 look to be reversed from the way mine were delivered. This opens allows mounting the work lights higher and in the recess area of the rear roof line as shown here:
I made some simple brackets to mount the work lights using the existing lollypop light bracket, shown in primer:
I have a B2650 with turf tires (larger tires compare to R4) and I had to completely remove the capping around the garage door, re-frame and got the aluminium done by the same company that installed the door a few years ago. All together $400 but so worth it, warm tractor on startup, snowblowing in t-shirt and sandals! Current door height is 85" and I just clear the weather strip.