How to tell if modules are leaking/ how bad is it, if they are ?

The quickest way is to run the down and dirty test take the cover that exposes the fuse in the safety plug the big orange plug remove that cover but the plug back in just stick it in there but don't push it down and now measure from your red lead touching one of those silver nuts that holds the fuse in the orange plug and the bolt that goes through your battery tray to the frame of the car that should count down to zero in the DC volt scale with what's sitting there on your tray and whatnot I bet it stops counting at about 79 volts or something like that 77 whatever can't make zero It's leaking the whole assembly but that should be putting a light on every so often in the car with a cheap scan or you can clear the codes twice and continue driving. But all that mess you have there needs to be cleaned up quick fast in a hurry That's really messy all those bus bars nuts they can go in the kids rock tumbler with some mild abrasive tumble for about an hour and they'll be like brand new The cable ends the same way there's some liquid you can use vinegar and salt whatever that makes that chemical reaction cleans up that stuff pretty nicely. If you can get hold of old CRC the heavy duty electrical contact cleaner that will blast those cable ends pretty clean Don't worry about the lead being darkened and whatnot the copper It should still measure out okay If it scares you you can buy replacement cables. But if you're going to go that deep you might as well be looking to get a new battery It is worth it It is a keeper car unless it's rusted in the rust belt all dented up or something just because it's old it's no excuse It's a Corolla it'll last five or 600k fairly easily.

 

Then you just check each module from its terminal post to the bottom screw hole that held all of the modules down to the tray that's like 56 little screws so stick a probe in there and a probe on them positive or negative terminal and see if you get a reading anyone you get a reading on market with a red sharpie or not supposed to be able to get a reading That's usually the major leak point on these prismatic modules the aluminum sided things