I've noticed for the past year that the MFWD indicator in the instrument cluster of my 2720 seemed to be operating sporadically. When in MFWD sometimes it would light and other times it wouldn't. Then a couple weeks ago it stopped working completely. I looked in the Technical Manual and saw that the switch was a spring loaded DPST with only one set of contacts used. When in 2WD the switch plunger is pushed in, breaking the circuit. When in MFWD the plunger is released, closing the circuit. My switch was open all the time. It's odd that they designed the lever such that the default 2WD position of a spring-loaded plunger switch was "pushed in" and under tension all the time.
Fortunately the switch is very easy to get to and is located on the left side of the transmission housing at the bottom of the MFWD engagement lever. The same switch (LVA11188, $22) is used on the 2320, 2520, 2720 and Gen-1 2032R. Although it is mounted a bit differently on the 2320.
The switch is secured to the bracket with (2) 7mm bolts with a small threaded plate instead of nuts. The bracket is secured to the side of the transmission with a single 12mm bolt. It was much easier to remove the bracket first and then remove the two 7mm bolts after the bracket was off. Care is needed when tightening the two 7mm bolts as the tiny threaded plate only has about 2 threads and it would be very easy to strip. Once the bracket is removed it is very easy to remove the 7mm bolts, replace the switch and reattach.
The switch mounting holes are not slotted but there is some slop in the holes so a wee bit of adjustment is possible to obtain a positive engagement of the MFWD lever.