P3000 and melted busbar harness

I recently replaced 2 modules in the HV pack. Everything seemed fine initially, but then the battery monitor started to read abnormally. It would charge more than discharge until eventually throwing a fault at block 11, accompanied by the awful smell of burning plastic.

The damage is pretty apparent in the orange harness where block 10 and 11 meet. You can also see the plastic sticking to the electrodes poking out the modules.

Is this just an issue with how I reset the harness and it created a short?

 

All of the bars are soaking in a vinegar bath now. Didn’t even think to peek at that one specifically. It didn’t stand out though, they are all pretty corroded.

I suspected torque could have been the issue. I’m an extreme amateur at any kind of car maintenance and just went as tight as what seemed right. I’ve since gone out and bought a torque wrench and would reinstall the bars at 48” lbs

 

Well I can’t help you there. Just assume it’s one of these greasy old things pictured here. None look significantly different from the others, besides one being more blue. But I know it wasn’t that one.

Anyways, does this reasonably sound like user error and that I’m good to give it another go?

Also, is it worth throwing some noalox on these? Whoever was in here before, be it manufacturer or whoever left the busbars slathered in some grease. Wasnt sure if I needed to reapply anything

 

When I first got the car a few years ago, I had to rebuild the battery then as well and they already looked like this. I’m going to look into new ones because I plan to tear it apart and rebalance it.

I can’t stress that this car is my intro into electrical systems and automotive maintenance in general, and it feels like I’m hitting every bump in the road. So for any future readers who are like me and trying to do the job without taking the time to educate yourself, consider this a lesson in following torque specifications, and just buy the right tool the first time.

I reassembled the busbars, made sure to tighten every 8mm nut to 48” lbs and now everything runs just fine. The readings in Dr Prius look totally normal.

Next up I’m going to look into one of those 4 channel battery charging kits so I can get some hard numbers on how these modules are discharging. So far I’ve only been able to go off the resting voltages, and I’d like to avoid having this issue in another 2 years if possible.

 

I would guess a fair number of people driving 20 year old cars aren’t doing it because they have spare thousands lying around. From lurking the forum, I’ve seen buying new packs vs modules has been debated to death. Personally, I enjoy the tinkering, but the advice is noted