Installed new terminal posts, and now there’s no power anywhere…

[KoveKim]

I just want to preface by saying I promise I’ve done hours of painstaking research for the last 3 days trying to figure out the issue and how to solve this. I’ve literally stayed up til 4am with a headlamp on my head just messing with wiring, fuses, and grounding cables. I’ve used Google, I’ve searched on here and every other 240SX forum, I’ve watched many Youtube videos. I’ve taken my multimeter to the wires, grounding points, fuses, everything that’s obvious. There’s too much conflicting information.

Here’s the issue: My car was running fine before this whole ordeal (it had some bogging issues which I assume is a vacuum leak or bad gasket, idk yet). On the positive terminal post, there’s this little black connector, it literally hooks on to the positive terminal. It looks like a little black box with 2 plugs going into it - there’s 1 thicker wire that goes to a long connector, and then 2 thinner wires that go to a single stubby connector. That black box was corroded so bad, along with the positive terminal, that one day the car was getting no power. I’ve had experience with loose terminals before so I tried to just wiggle it on better and tighten the bolt. Bolt broke right off, so much rust and corrosion.

Pics:
https://ibb.co/n3RmT61
https://ibb.co/NYW5b0h

Because it was so messed up, the car wasn’t getting any power anywhere. No cranking, no lights, no clock on the gauge. The AGM battery is brand spanking new so that’s definitely not the issue. So I decided to cut off the positive terminal and splice on a new one, but I had to also cut off that black box because of all the corrosion and gunk in the plugs.

There were no other major electrical issues before I cut it off and put on new terminal posts. I didn’t tamper with anything other than the end of the positive cable, the wires connected to this black box, and then I also replaced the negative cable - hooked it up exactly as it’s supposed to go, made sure the grounding point was clean bare metal, I literally didn’t touch anything else.

Here’s my current wire setup:
https://ibb.co/TryKBRt

Here’s the other wire setup I tried but didn’t make a difference:
https://ibb.co/C5KsFzq

I’ve cut, stripped, crimped, and redone this setup about 3 times now. I decided to leave it at this to separate the wires because initially I just put them all into a single ring terminal. But none of these setups work. I’ve tried putting the ring terminals onto different positions on the positive terminal, I’ve even tried putting it onto a 100amp fuseblock that connected to the positive terminal. Nothing.

The reason I did it all this way is because I read many times that people cut off that black box with no issues, saying that they did exactly what I did and everything worked fine… But to be fair, those statements were referring to other Nissans because there is almost no information on this thing when it comes to the 240.

I’m hoping that someone finds the issue obvious because I don’t. I’ve taken my multimeter and tested the wires, the battery, the fuses, everything… I have absolutely no clue why cutting off that black box completely killed power to the whole car. It doesn’t even appear to have a fuse in it, and it’s straight up just connecting the wires to the positive terminal… This makes no sense to me.

Please help me, I need guidance, wisdom, ideas, anything. Heck, if someone can even just send me a new black box with the connectors (with some slack on the wires so I can splice it on) I’ll pay for it. I just want this car to run again.

[VStar650CL]

I can't find a WD for it either, but I'd say there's a good chance one or both of those smaller wires is a fusible link and maybe it's blown. You can use voltage drop with your meter to find out where the power isn't, that's a much better method than ohming wires. Just turn the key on and look for where you find a big voltage between one end of a wire and the other.

[NukeKS14]

I agree with Vstar here; sounds like you may have blown a fuse. Start checking your larger fuseable links in the box and see if anything's blown.

[KoveKim]

I agree with Vstar here; sounds like you may have blown a fuse. Start checking your larger fuseable links in the box and see if anything's blown.

I can't find a WD for it either, but I'd say there's a good chance one or both of those smaller wires is a fusible link and maybe it's blown. You can use voltage drop with your meter to find out where the power isn't, that's a much better method than ohming wires. Just turn the key on and look for where you find a big voltage between one end of a wire and the other.

Thanks guys, I’ll pull up ChrisFix’s fusible link video and see what I can put together. The issue is that I can’t find that black box for my model anywhere, although I did find a similar one for the Hardbody on Ebay. So yeah it’ll be a lot of splicing wires and hoping for the best. I’ll order some supplies and report back with fusible link progress.

[KoveKim]

Update… New alt fuse didnt do anything. Anyone please feel free to help guide me in the right direction because I feel so lost. Tonight I’m gonna try and trace the wires back as best as I can, but 2 of them are mounted onto the fuse box and the other (larger/thicker) wire just goes to the starter, but it looks fine. Plus the starter isn’t the issue anyway, the issue is that the car gets no power at all - not to lights, not to the gauge cluster/clock, to the ECU… nothing

[VStar650CL]

post6817410.html

The above technique works on hot cables too. Just turn the key on so there's a load, even though it doesn't seem to do anything. Then measure point to point along your power wires. You should see near 0V between points which should be connected. When you find a point where it reads 12V, you've found your disconnect.

[KoveKim]

Final update on this.

I checked the voltage of my AGM battery again just to make sure everything is as it seems. It read 0 volts. I don’t know how a 2 month old battery got to 0 volts, but oh well… Went to Autozone and pulled the trigger on a new battery. I’m keeping the AGM for now while I figure out warranty information.

​Anyway, I installed the new battery and bam, instant power; heard the chime and I was simultaneously furious and relieved. Somehow the battery went bad at the exact same time that I cut off that little black junction box… From there, it played the role of red herring.

So for anyone in the future who stumbles upon this, no - that black box connector on the positive terminal isn’t essential and as far as I can tell it doesn’t do anything, it doesn’t even have a fuse in it nor does it have fusible link wiring. You can crimp/solder the 3 wires into a single ring terminal and just bolt it onto the positive terminal.

PS. Always double check the battery first before diving into electrical issues.

[VStar650CL]

I checked the voltage of my AGM battery again just to make sure everything is as it seems. It read 0 volts. I don’t know how a 2 month old battery got to 0 volts, but oh well…

Broken terminal post inside the battery case. Not very common, but it does happen. Glad you got it straightened away!