Loss on sale of fixed asset. 11111

One of my client have income from trading and income from truck (Proprietor). Accounts of trading are maintained like trading and profit and loss account and balance sheet. But no accounts are maintained of trucks and in ITR income from truck is shown under Sec 44AE. Due to non maintenance of accounts of truck depreciation has not been charged on truck. Now in current financial year my client has sold all of his trucks and due to no depreciation charged in previous years loss have arised in selling of trucks. Now my query is that where this loss should be show whether in profit and loss account or in capital account.