My $300 electrical nightmare

[85toycrawler]

Ok, so I have been searching this all day and still haven't figured it out. Not to mention I have just made it worse.

I bought the car a few days ago from a buddy for $300. It had been sitting since 2007 so I changed the oil, drained the fuel, put in a new fuel pump and filter.

Basically, none of my gauges work, no dash lights, I only have Hi Beams, no tail lights, no turn signals.

I looked under the dash to find a wiring nightmare. There was a aftermarket alarm system in there. I started tracing wires and pulled the alarm out. I keep popping the Illumination fuse, so there has to be a short some where or a bad ground. So besides that issue, now after pulling the alarm out the car has no power to the ignition or the fuel pump. So it won't start. Can someone please point me in the right direction to figure all this stuff out. Thanks in advance

[BigTDogg (MA)]

You're on the right track. You have a short or bad tap or some other issue with the clearance illumination circuit.

In here: http://www.nicoclub.com/FSM/300zx/ you'll find wiring diagrams. It will take time, patience and a DMM, but you can repair the alarm instal and fix the circuits. Otherwise provide the information to someone else who is good with wiring an have them trace it out.

Sorry there is no magic pill for this. Hacking up factory wiring is one of my biggest pet peeves.

[Fearspect]

For what you paid, and what you will get (for a minimal cost, but a lot of time), you may just consider straight up cutting it all out and throwing in new harnesses...

If you do go that route, might as well throw in a 95+ harness (and CAS) to support the new style fuel injectors.

[BlackWidowZ]

always unhook the battery before messing with wires. you probably have some some blown fusees besides besides the illumination fuse.

[85toycrawler]

I'm not getting any power when I turn the key on.. I get the beeping from the door being open, but nothing else. No radio, clock, power to the fuel pump etc..... One of the wires did arc on some metal when taking the alarm out. It is the red and white wire that goes into the lock and tumble..... So I'm assuming I have no power to my ecu....

[85toycrawler]

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Update. Realizing I didn't have power to that red and white wire, I decided to do a little experiment. I jumped that wire straight to the battery with a long wire. Not only did I re-gain power to my fuel pump and such, the tach, oil pressure gauge, and temp gauge all started working. I will check the speedo later when I drive it. I also have more dash lights... (apparently I'm low on windshield washer fluid)

So my question is, how bad of an idea is it to run that wire permanently? With a fuseable link and relay.... I know it's not the best way to do it, but I'm not great with electrical and I cannot afford to take it to a shop at the moment.

Going to check the lights now, hopefully they are good too.

[BlackWidowZ]

This could help you please-help-my-z-won-t-start-t572321.html

[BigTDogg (MA)]

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Update. Realizing I didn't have power to that red and white wire, I decided to do a little experiment. I jumped that wire straight to the battery with a long wire. Not only did I re-gain power to my fuel pump and such, the tach, oil pressure gauge, and temp gauge all started working. I will check the speedo later when I drive it. I also have more dash lights... (apparently I'm low on windshield washer fluid)

So my question is, how bad of an idea is it to run that wire permanently? With a fuseable link and relay.... I know it's not the best way to do it, but I'm not great with electrical and I cannot afford to take it to a shop at the moment.

Going to check the lights now, hopefully they are good too.

It's bad, find out what that wire goes to and fix the connection. This will take time, but it's the right way to do it.

Below is the holy grail of wiring diagrams:

http://www.ttxtz.com/tech/lee/

For what you paid, and what you will get (for a minimal cost, but a lot of time), you may just consider straight up cutting it all out and throwing in new harnesses...

If you do go that route, might as well throw in a 95+ harness (and CAS) to support the new style fuel injectors.

Different harness. What he's describing is a chassis harness, no the EFI/ECCS harness. But I agree if changing that harness to go to the 1995 variant.

[EvanW]

Below is the holy grail of wiring diagrams:

http://www.ttxtz.com/tech/lee/

Wow! Thank you very much for this!

Evan