[85nissan]

Bought a 85 300z turbo , ran great, for about a week , got in it oneday wouldn’t start , no crank , bought a new battery, when installing smelled something burning. same prob. Won’t start ,

 

[rogoman]

The burning smell was probably a fusible link that burned up. On the passenger side of the engine compartment near the firewall, there's a box that contains six fusible links. One of them is probably burned up; by looking at each one, you should be able to see the bad one. Disconnect the battery and use a multimeter to find the short to ground. You can download a copy of the FSM for your car from this site:

Nissan 300ZX Service Repair Manuals

Nissan 300ZX Service Repair Manual PDF Free Download 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996

diyservicemanuals.com

The section EL.PDF contains the wiring diagrams that you'll need for finding the short.

 

[smj999smj]

It's been awhile, but IIRC, a Z31 has the fusible links at the positive battery cable like this: