cotton in the bottom of the chamber can be compacted to at least some extent to facilitate receipt of additional cotton into the chamber during continued harvesting thus although optimal module building may not occur in the event of failure of one or both of the compactor position sensors 62 a and 62 b a reasonably effective compaction routine is provided referring also to fig5 a high level flow diagram is shown including preferred steps for operation of compactor controller 66 in a fault tolerant mode in the event of a faulty auger pressure signal or absence thereof at block 94 augers 32 are operating to distribute cotton within compactor chamber 18 controller 66 will determine if an auger pressure signal is present as denoted at decision block 96 if yes controller 66 will determine whether the signal is good for instance within a predetermined or correct value range as denoted at block 98 if yes controller 66 will operate the compactor in the normal manner for instance responsive to auger pressure signals as denoted at block 100 returning to decision blocks 96 and 98 if controller 66 determines that the auger pressure signal is not present or is not within the correct range controller 66 will operate in a fault tolerance mode which can involve for instance operation of augers 32 for a predetermined auger operation time period controller 66 will time the operation.