1990 Nissan 300ZX

Electrical problem
1990 Nissan 300ZX 6 cyl Two Wheel Drive Manual 170000 miles

I installed an after market radio in my Z and everything worked fine. Then I tried to install an amplifier for a subwoofer. The wiring was left from the previous owner who had an amplifier, so I did no re-wiring whatsoever. Unfortunately I didn't disconnect the negative cable from the battery before I connected the power (12v) wire running from the amp to the positive terminal of the battery and there was a small spark when I connected that wire.

Now the car wont start; it won't even turn over (crank). There is full power to everything. The radio works, headlamps, windows, everything. Its similar to when when you turn the key on a car that is standard but you haven't pushed the clutch in. Everything is lighting up on the gague cluster just as it normally would.

Any suggestions?

May 7, 2009.

Hi frank_dux,

Thank you for the donation.

Seems a power supply is preventing the stater circuit fron operating. I have the schematic here which should help you diagnose the problem. It most probably is a blown fuse.

May 7, 2009.
Thanks for your response. Any idea which fuse it could be? I checked all the ones that were ignition related but they were fine. Could it be a fuse that is not ignition related?

May 8, 2009.
Sorry for the delay in answering. Seems to be having connection problems.

After going through your question and the schematic, I realised I forgot to mention the anti-theft system. Since you have power to the dash, it should not be any fault with the power supply as they have to pass through the ignition switch and there is no specific starter related fuse.

It could be caused by the anti-theft system and you have to check if the relay is working when cranking.

Check the clutch interlock relay power supply as well.

May 9, 2009.