Return line has issues where duct is either crushed or damaged somehow. With return bypassed and door open at unit, was getting 151cfm out of supply register upstairs. Need Matthew to coordinate with General Contractor Spence Barker 209-430-4400, please let Spence know this job is for Mr. Willis, he does a lot of work for him. Need to coordinate for roof to be removed and then access situation with return duct.