No Power past fuse box

[Rostr02]

Well I have been graced with an electrical gremlin and have not the foggiest idea on how to progress past this part.

JDM 2JZGTE with T88 greddy single turbo.

 

So I have done a remote battery install into the boot with an inline breaker, power feed directly to the fuse box. Battery is double grounded in the boot area. 12V fuel pump mod and had great pressure. All lights working with the exception of the turn signals that I was less than worried about. Everything was fine until I ran the power feed from the fuse box bolt to the starter. I then tried to start the car heard a click then everything is dead.

I disconnected the starter and went back to the way everything was pre power failure. I have no fuses that are blown under the bonnet or the driver side fuse box. I have checked continuity to all of the fuses and all are good as well just to be actually certain they were not the cause.

I have not gone through all of the relays to be certain they are not the cause though, I have the same continuity for all of the relays under the bonnet but have not gone through all the relays in the foot well.

If anyone has any pointers as to what the hell I actually did and how to fix it I greatly appreciate it.

 

Some before and after pics of the progress so far.

 

Thanks,

Bob

[Swampy442]

Are the battery terminals tight?

[Rostr02]

Yes for sure. They are bolt in terminals and have power all the way to the fuse box. But then as soon as I bolt everything down the bolt meter drops. I have no clue at this point. Obviously the power is connected at this time, this was right after I did the install

Edited August 15, 2022 by Rostr02 (see edit history)

[Homer]

Does it do the ‘click’ every time you try to turn the starter over or just click once and then is dead until you power off? If it goes dead after one attempt it means you have a current but inadequate amps to engage the starter. I might well be spelling out the obvious here so apologies in advance.

It sounds like you’ve checked through all the positive side of things so grounding would be next to check. Have you gone through all the oem ground points and ensured they’re all installed and have a good connection (metal to metal)? There’s a lot of hidden ones so it’s worth doing a full check. 

[Rostr02]

I have zero power at all past the fuse box. I did until I ran the power feed to the starter, now there is nothing. I am hoping it is something I can sort out, I am just hoping it is not the ecu. 

[Mike2JZ]

Checked the 120amp fuse in the fusebox? You will need to remove the fusebox from the plastic housing in order to check continuity 

[Rostr02]

Mike thanks for the response, yes the fuse was pulled to check continuity. All of the fuses were pulled actually to check.

[mark brown]

Those earths to the body from the battery may be suspect, did you remove the paint before screwing them down to the body as the screws only contacting the metal are unlikely to provide an adequate earth for any significant current draw

[Swampy442]

Im trying to think here, where's your charging circuit, from the alternator? You've gone battery to earth, battery forward to the fusebox, where's alternator to battery?

[Rostr02]

I redid all my grounds today and added a few for good measure just in case. Still no go. 
 

i have power to the fuse box but if I check power at the main nut there is only 2.5 volts, if I disconnect and check the line without it being attached to the fuse box it is the same reading I am getting at the battery. 
 

i ordered new alternator fuse just in case despite it not being blown and having good continuity. And 4 new relays for the fuse box just in case. Should be in in a couple days and see if one of them fixes it 

[Swampy442]

See my comment above

[Rostr02]

Swampy, the alternator runs into the fuse box via the factory wires. I traced them all and all alternator wires are intact and connected to the alternator. Even took all the wire loom off just to make sure. 

[Swampy442]

So how do you charge the battery from the alternator?

[Rostr02]

Sorry for the late reply back I had a few crazy days at work and no chance to work on the car. I ordered brand new resistors and min fuse for the box. Sanded all the ground areas and placed some dielectric grease down. Reconnected the battery and viola she now has power. 
 

Starter turns over but can’t get her to fire up yet sputter a bit but won’t start. This is a step in the right direction at least and am happy that whatever the hell I did something worked. Thanks everyone for the help. Now to get it started.