Solo 401K Contibutuion allow when there is a Net Loss

My business is just starting out and I'm not turning a profit yet and I've got some income ($25k for example) but my deductions are running $35K, so I'm at a net loss of $10K for the year. Can I still make a contribution to a Solo 401K or does the business have to be at a Net Profit to do this? and if so is the outcome, that the net loss would increase as the contribution would reduce the income?