[major]

Originally Posted by monkmonkey

That 500 amp fuse on the left side is blown, which is why the contactor won't work.

How do you know the 500A fuse is blown? If it is blown, why did it blow? Without knowing why it blew, you should not simply replace it with a new one. Assuming it is blown, you can trace out and track down a short if that was the cause. Correct the issue and then replace the fuse.

And why would the blown fuse interfere with the contactor working? Hint: It does not.

Originally Posted by monkmonkey

Will any 500 amp fuse work that will fit or is there a certain type?

Fuses have ratings, and there are reasons for those ratings. I kind of doubt that fuse which is in there meets the requirements. It does not instill me with confidence, similar to my opinion of the workmanship of the entire installation. Many fuses having that form factor carry a 32 volt rating.

So, I recommend a proper fuse rated for at least 100 Volts DC and 400 Amps.

[monkmonkey]

Originally Posted by major

How do you know the 500A fuse is blown? If it is blown, why did it blow? Without knowing why it blew, you should not simply replace it with a new one. Assuming it is blown, you can trace out and track down a short if that was the cause. Correct the issue and then replace the fuse.

The fuse does not have contiguity when measured in ohms. Plus, an auto parts store confirmed it. That fuse sends power to everything past it, so that would include the contactor and controller.

The fuse used was a Buss 500amp. Don't know what the volts rating is.

[mk4gti]

The contactor should still "work" as it is controlled by the 12v side. But yeah if there is no HV in, there won't be any out...

Take the time to study how these circuits are *supposed* to be wired, rip everything out and start fresh. Before you hurt yourself !

[major]

Originally Posted by monkmonkey

The fuse does not have contiguity when measured in ohms. Plus, an auto parts store confirmed it. That fuse sends power to everything past it, so that would include the contactor and controller.

Originally Posted by major

...... If it is blown, why did it blow? Without knowing why it blew, you should not simply replace it with a new one. Assuming it is blown, you can trace out and track down a short if that was the cause. Correct the issue and then replace the fuse.


And why would the blown fuse interfere with the contactor working? Hint: It does not.

The contactor will still close even with a blown power circuit fuse if the control circuit (that powers the coil) is intact. The blown 500A fuse is not the reason the contactor doesn't work. Although you are correct, it would not conduct high current to the controller.

Why did the fuse blow????????

[PStechPaul]

At last report I thought the OP's EV would run for a while and then lose power or become erratic and then stop. With the fuse blown this should not be possible, and otherwise the fuse is not in the correct part of the circuit and not providing proper protection. Is it still mounted so that the current goes through the steel nuts on the studs? They may have overheated and caused the fuse to become intermittent and it might not have continuity at a few volts from a multimeter, but full pack voltage might "jump" enogh to get current for a while.

But as I said, this seems like a lost cause. The OP needs to get hands-on professional (or at least skilled and experienced) help. This is turning into a comedy/tragedy of errors.

[monkmonkey]

My fuse arrived today. I reworked the battery setup so now the right top battery is now the aux. The yellow cable is now connected to the + aux. Now the accessories do not work, nor the ignition. But I can turn the car on/off with the on/off switch under the hood. I also connected the red coil contactor wire to the fuse connection. Now it doesn't go on/off as it did before.

I drove it a couple miles and it did well, even though the batteries are low and not charging.

[Ziggythewiz]

Sounds like traction and AUX batteries/circuits are being mixed with wild abandon. The two should not touch. It's a wonder you've survived to page 4 of this thread.

[monkmonkey]

..........

[monkmonkey]

Originally Posted by Ziggythewiz

Sounds like traction and AUX batteries/circuits are being mixed with wild abandon. The two should not touch. It's a wonder you've survived to page 4 of this thread.

The two are separate now.

[Ziggythewiz]

Oh...ok. I thought you meant the top traction battery was now the AUX.

Maybe it's time for a new, clean wiring diagram?

You should probably do two, one with physical locations and existing wiring colors, and another that's purely logical to make things easier to see.