03 mustang 3.8 is the code p1633 expensive fix

Question

my check engine light is on I keep replacing fuses for this to go out

Answer 1

P1633 Keep alive memory power

What you have is a short which is power to ground, being a electrical short , the fix depends on the repair, a inspection of the harness is going to have to be done, if the short is easily found the repair is relative inexpensive, if not and the circuit in question is bridged this would depend on the repair place