Should our son,a full time college student that we support, received a W-2 scholarship /grant / interest received / dividends receive from investment, file a 1040?

It depends on the amounts. See the dependent filing requirement below.

 

Single dependents—Were you either age 65 or older or blind?

No.

You must file a return if any of the following apply.

1.Your unearned income was more than $1,100.

2.Your earned income was more than $12,200

3.Your gross income was more than the larger of—

a.$1,100, or

b.Your earned income (up to $11850) plus $350.