Shorted wire - voltage drop @ ignition coil wire

[alex44]

Hey so I'm having a bit of trouble with my ignition after someone hit my 1978 280z in a parking lot which caused the 12v ignition wire (black/white) at the ignition coil positive to get pinched and shorted to body. This caused the ignition switch fusible link to smoke (and some smoke off the ignition switch itself) when I was cranking the car over before I knew the 12v black/white wire had shorted.

 

I have temporarily hotwired a on/off toggle switch direct off the battery to the coil so I could start it, it fired right up which tells me it's something to do with the wiring/ignition circuit. I have replaced the ignition switch with no luck. I am reading 12v at ignition coil from the black/white wire when key is in ON position but as soon as I engage the starter motor the voltage drops to around 1, then jumps back to 12v when I release the key. I have checked continuity on all the fusible links but Im going to replace them soon just in case, glass fuses at fuse block are all good.

 

I'd like to fix the black/white wire or rewire it to another source that provides 12v key ON and 12v when engaging starter but I haven't been able to find any so far when poking around. There is no ballast resistor on the car, its running a 280zx matchbox distributor with a z31 turbo ignition coil and have used this setup for years without issues.

 

Any help with this would be appreciated I really am not the best with diagnosing electrical gremlins..

Edited February 26, 2021 by alex44