Please help... Electrical problems!

[bottombury]

So my battery died on my '88 300zx one day because the door wasn't shut properly and the interior lights stayed on all night and all day. That's when everything started going wrong...

I tried to jump start the car but crossed the terminals of the battery while trying to boost my car. It wasn't plugged in for a long time though... under ten seconds... the booster car was fine though...

I went and replaced the battery and when I opened the door there were no lights on. I started to worry that I damaged the vehicle's whole entire electrical system. Then I placed the key to ACC nothing turned on... no interior lights, no radio, and no door lights, but I could hear the engine priming. I got excited and started the car. And it started!!

But still nothing turned on inside... tried the headlights and it turned on but it didn't flip open. Then I revved the engine and everything turned on!!! Everything was functional, the radio, internal lights, digital dash, horn, etc...

When I turn the car off to ACC everything turns off again and there's absolutely no power as if the battery has been disconnected... but I can start the car and rev the engine a bit and everything turns on and I can drive it just fine.... and again when I turn my car off, it seems like the battery gets disconnected and there's no power to the vehicle at all...

So my question is what's wrong and why is it doing this?

I'd appreciate any help...

[evildky]

I'll assume you alreay checked ally our fuses, I'm not exactly sure how the power is routed in the Z31, maybe AZ bum can elaborate but basically you have hot feed going to your fuse panel, could also be a relay, it sounds like it's burnt one or the other up, could also be in the alternator, you can have autozone test your alternator for free, digging intot he fuse panel is a whole other ball of wax, talk about PITA, and it's integral to the harness int he Z31, tracking it down will likely be the most difficult part, sorry I can't be of more assistance

[Osiris1977]

Bone head me did the same thing (didn't pay attention to what I was doing, and crossed the jumpers when I attached it to the battery). Anyway your problem may lie in your in-line relays. Check all of them, one of mine had blown when I did that. All of the fuses in the inside fuse box were OK, but one of the relays/fuses under the hood blew. You have all the same symptoms of my problem. The revving the engine thing will only work for a short time, at least that was my case. Thanks to evildky and AZ-bum I figured that out. They are Nissan/Datsun fixing gods.

[Osiris1977]

One more thing...I had to replace my alternator when that happened because the voltage regulator also blew, and unfortunately that car has an internal regulator. Cost me around $100 for a new one. Just chalk it up to an expensive mistake you will hopefully not make again.

[bottombury]

Thanks for your replies!!! hehe

I jiggled the relay wires and everything turned on...

How do you know if you blew the voltage regulator? because everything seems to be fine now...

[Osiris1977]

Before I screwed everything up the car was running fine, and the voltage needle on the gage in the car was in the "good" zone. After I fixed the blown inline fuse problem the voltage needle would sit at just above the 8 volt mark, even when driving. Every so often the needle would spike up to between the 15 and 18 volt marks. I replaced the alternator, and the needle sits nicely between the 12 and 15 volt area where it should be whether at idle, or while driving.

[bottombury]

THANKS SOOOOO MUCH!!! You don't realize how much I appreciate your replies!!! It helped a ton and set my worries aside because I love my car!

THANKS THANKS THANKS HEHEHE