thefro526
03-12-2013, 07:24 AM
So, I've been having a tonne of electrical problems with my S14 over the past few months. Searching on the internet has been somewhat inconclusive, so I figured I'd take my experiences and information and put it into a thread just in case some lost soul ends up where I've been.
Before you start hacking and tracing wires, I suggest you gather the following:
Wiring Diagram http://www.240edge.com/manuals/96_240sx/el.pdf
Multimeter
Test Light
Now onto my issues. My S14 is relatively low, some would considered it slammed, whatever. I tucked my harness into the fender a long time ago, and never really had any issues. In January, I finally put my snow tires on, and hadn't realized that they were about 1/2" taller than the tires I was previously running. After having too much snow fun, my car started to act strangely. It wouldn't start right, always seemed to be running a bit weird and my electrical system always seemed to be dying. Then, one day, I walked out to my car, put the key in the ignition and nothing in the car worked aside from the 12V Constant circuits.
I traced those wires as best I could at the time, ruling out the logical sources; 30a fusible link, battery cable, etc. Finally, I dug into the fender harness.
http://thefro526.files.wordpress.com/2013/03/img_2312.jpg?w=640&h=856
In the picture above, you'll see three white wires that are noticeably larger than everything else. The white one without a stripe is your 12V Ignition Constant. This wire happened to be worn through in a section, which was preventing power from getting to the ignition switch and then to the rest of the car...
A few weeks later, the car died on me again, but this time it started breaking up while a relay clicked quickly. Checked my harness to find this:
http://thefro526.files.wordpress.com/2013/03/img_2218.jpg?w=640&h=856
http://thefro526.files.wordpress.com/2013/03/img_2221.jpg?w=640&h=478
Turns out one of the low voltage signal wires that went to one of the ignition relays was broken and shorting to the chassis. This would prevent the car from firing when cranked. Good times.
Long Story short, I went through the harness, found all of the bad wires (17 total) and fixed/extended them before tucking them back up.
http://thefro526.files.wordpress.com/2013/03/img_2313.jpg?w=640&h=478
http://thefro526.files.wordpress.com/2013/03/img_2340.jpg?w=640&h=478
After all of that, the car still wasn't right. I had power at to the car, but not enough to make anything other than the clock work. This is most often a sign of a bad ground with too much resistance, though this wasn't my issue. Turns out, the take off connector/spade thing from the battery was corroded and measured nearly infinite resistance (maxed out my meter).
http://thefro526.files.wordpress.com/2013/03/img_2340.jpg?w=640&h=478
http://thefro526.files.wordpress.com/2013/03/img_2346.jpg?w=640&h=856
Cleaned it up, and all is well.
http://thefro526.files.wordpress.com/2013/03/img_2362.jpg?w=640&h=856
So yeah, hopefully someone finds this as a good reference at some point in the future.
Before you start hacking and tracing wires, I suggest you gather the following:
Wiring Diagram http://www.240edge.com/manuals/96_240sx/el.pdf
Multimeter
Test Light
Now onto my issues. My S14 is relatively low, some would considered it slammed, whatever. I tucked my harness into the fender a long time ago, and never really had any issues. In January, I finally put my snow tires on, and hadn't realized that they were about 1/2" taller than the tires I was previously running. After having too much snow fun, my car started to act strangely. It wouldn't start right, always seemed to be running a bit weird and my electrical system always seemed to be dying. Then, one day, I walked out to my car, put the key in the ignition and nothing in the car worked aside from the 12V Constant circuits.
I traced those wires as best I could at the time, ruling out the logical sources; 30a fusible link, battery cable, etc. Finally, I dug into the fender harness.
http://thefro526.files.wordpress.com/2013/03/img_2312.jpg?w=640&h=856
In the picture above, you'll see three white wires that are noticeably larger than everything else. The white one without a stripe is your 12V Ignition Constant. This wire happened to be worn through in a section, which was preventing power from getting to the ignition switch and then to the rest of the car...
A few weeks later, the car died on me again, but this time it started breaking up while a relay clicked quickly. Checked my harness to find this:
http://thefro526.files.wordpress.com/2013/03/img_2218.jpg?w=640&h=856
http://thefro526.files.wordpress.com/2013/03/img_2221.jpg?w=640&h=478
Turns out one of the low voltage signal wires that went to one of the ignition relays was broken and shorting to the chassis. This would prevent the car from firing when cranked. Good times.
Long Story short, I went through the harness, found all of the bad wires (17 total) and fixed/extended them before tucking them back up.
http://thefro526.files.wordpress.com/2013/03/img_2313.jpg?w=640&h=478
http://thefro526.files.wordpress.com/2013/03/img_2340.jpg?w=640&h=478
After all of that, the car still wasn't right. I had power at to the car, but not enough to make anything other than the clock work. This is most often a sign of a bad ground with too much resistance, though this wasn't my issue. Turns out, the take off connector/spade thing from the battery was corroded and measured nearly infinite resistance (maxed out my meter).
http://thefro526.files.wordpress.com/2013/03/img_2340.jpg?w=640&h=478
http://thefro526.files.wordpress.com/2013/03/img_2346.jpg?w=640&h=856
Cleaned it up, and all is well.
http://thefro526.files.wordpress.com/2013/03/img_2362.jpg?w=640&h=856
So yeah, hopefully someone finds this as a good reference at some point in the future.