I have a old trane roof top unit 1988 vintage model sfdbc174-ld serial c88j0026 type XXXXXXX-01-b where are the following controls located flc fan limit control do i have to remove the unit top section to get to it? also the H1 high limit fan fail switch ? AND H2high limit discharge air where are these located and how do you get to them one i think is located next to the dwyer air switch? Thanks for anyones reply the FLC is what i realy have to get at.