where do I deduct a vehicle in turbo tax for the tax deduction 179?

[DoninGA]

You need to be using the TurboTax online Premium editions to report your self-employment income and expenses.

See this TurboTax support FAQ for entering your self-employment expenses - https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/enter-self-empl...