Thread: IGN keeps going dead....PLEASE help!

Okay....had a wiring issue with the front O2 sensor on my 96 200sx se-r. I thought I fried the ecu when I wired it up wrong. When I turned the key, everything went dead. The ACC position still had power, but the IGN position was dead.

Well, wiring is fixed, and I just put in my Nismotronic B13 ecu. However, the IGN was still dead. Checked ALL fuses, and they were fine. Last thing I checked was the fusible links next to the battery. They looked fine. Just for giggles, I switched the RADFAN 30A, with the IGN 30A link and wouldn't you know......when I turned the key to IGN and eveything worked again. Fuel pump primed, all accessories turned on, etc.. Well, when I tried to start the engine, BAM. Everything went dead again. But this time when the key is in the ON position, there is still power, but it looks weak. Like the battery is drained. The battery checks fine. I don't have any more fusible links to replace what's in there. I checked all my wiring, and couldn't find any problems. Ever since I hooked the O2 sensor up wrong, this keeps happening even though the wiring is good now.

Also, as soon as I plugged in the NismoTronic ecu, the radiator fan came on as soon as I turned the key to IGN. What's up with that?

I HAVE to have this POS running by MONDAY. I would GREATLY appreciate ANY help I can get!

Sounds like you need to replace the relay for both rad and ign now you swictched them. Pick up some more fuses and fuseable links.

Also, double check that 02 sensor wiring again. Search the forum for the thread on this. The wiring colors are described along with the best install option for grounding.

Seems like you know what to do. GL bro.

I haven't messed with the relays. All I swapped was the two fusible links. After swapping them before it went dead again, the rad fan came on. So I'm not 100% sure it's the links, but I don't know of any more fuses to check. It's like it's not fully blowing a fuse every time I try to start the engine. Would a bad relay cause that?

The last time I tried to start it, I only had the signal wire connected on the O2 sensor. Black on the sensor end, to the white on the harness end. I'm pretty much out of ideas....I don't know why it would keep doing this once the problem was corrected.

Okay....I've checked ALL the fuses again, and none of them are bad. The fusible links don't look blown either, but I guess they are.

It's only when I go to start the engine and energize the starter circuit that everything goes dead. I tried changing relays, and that didn't solve anything. I checked all my wiring yet again, and can't find anything that looks like it might be causing a short. I can't think of anything else that would be causing this. Is there something that I'm overlooking that I'm not aware of?

bad battery connection or grounds can cause issues like you described.

I put new terminals on it a few weeks ago, and regrounded while I was at it. The car ran before this little sensor mishap.

I'm going to get some more fuse links and take a video of what it's doing. Because I have full 12V with the key in the ACC position, but weak to no power in the ON position after I put in a new fuse link, and try to start it.

What harness are you using? Just unplug the O2 and try again. It could be the IGN switch as well causing this.

I'll be able to mess with it again tomorrow. What all could be damaged as a result of the front O2 sensor being wired wrong? Never thought about the ignition switch itself. That would suck.

Here's some videos of what going on with the car. I also noticed this time that when I turn on the park lights or headlights, the ACC power gets cut? I've went throught the FSM countless times tracing the circuit. I've replaced ALL fuses, links, and relays, but the problem keeps persisting. I guess I'll try pulling the ignition switch next.

YouTube - 4-13-11 012.MOV

YouTube - 4-13-11 013.MOV

I like coheeds answer I spent a week testing wiring on a car countless hours and you know what the problem was...... the dam battery terminals had corrosion on them....of all the problems that could went wrong...the battery had a bad ground.