Mazak v-15n spindle load issue

[TWPguy]

Hey all, we have two late 80's Mazak v-15n's here at our shop that are basically identical(except for size of the tables). Just for easier reference, small table is Mazak 1 and larger table is Mazak 2. Last week Mazak 2's fr-se spindle drive decided to blow. It wasn't even under a load, guess it was just its time. So the consensus around the shop is that we needed Mazak 2 to stay up and running. So swiped fr-se out of Mazak 1 set all dip switches accordingly, and all seemed good. Shortly after our operator freaked and came up to get us because the load meter is acting weird. On a light cut it will show roughly 40-60%, and when his program takes a cut about twice that size the load meter shows zero?! So I downloaded the manual from Mits. website and found it says to set load meter, to flip sw6-6 to off position, and adjust vr15 until load meter shows 120, then flip sw6-6 back on and hit reset on drive; however, the most I can get out of load meter when I adjust vr15 is 90. So am I missing something in this book or do I just need to tell my operator to just deal with it?