Hello all, I am very new here and new to being a Honda fit owner. I purchased it off my sister, who had a few problems with it, but overall it was still functional. I've been having a problem with a battery drain. If I leave the car sitting for a couple days, it won't start back up. I've had to recharge the battery several times, including replacing it entirely. I thought I had fixed the problem when I unhooked some faulty door-locking mechanisms, and I think that helped, but I'm still dealing with the problem. I think there may be a few things wrong, but I'm not sure what.
I've gotten advice from a mechanic I know who's taken a look at it to replace the battery cables, since they're looking pretty shabby and I can't seem to get a good connection, even after some good cleaning. However, taking a look inside the hood, this doesn't look like it'll be an easy job. I have two main questions:
1. Has anybody here replaced the battery cables on a 2009 Honda Fit and have any advise or knowledge on what that involves?
2. Does anybody have any guesses on what might be causing the battery drain?

(Additional information: I've already done a parasitic drain test but the multimeter showed normal amperage. Not sure where to go from there.)

 

Two common sources of parasitic battery drain with Honda Fits- The a/c clutch RELAY. It is located under the hood/ engine compartment, behind the left/ driver side headlight inside a small plastic enclosure. A bit difficult to locate but a relatively easy/ inexpensive fix- new relay. The second source is the number 1 circuit, the fuse in the upper left of the fuse panel inside the car, to the left of where your left foot rests under the dash while driving. I was not able to pinpoint the exact source of the drain so I simply attached a fused switch on the dash to cut off power to that circuit when the car gets parked.

 

There are a number of videos on YouTube showing how to track these down. You have to hook up a meter and then check it for hours after the engine has been turned off because the drain may not start until some time after. Once you've confirmed a drain you need to check the individual fuse circuits one by one to identify which one is responsible. This is a long drawn tiresome process. Most shops don't want to do it because of this. I watched one video where they traced the problem to the power steering system. Probably a bad circuit board inside it but not serviceable so they had to replace the whole thing,

You should begin by making sure there is no add-on accessories on the car, no modifications, nothing plugged into the USB ports etc. No camera hooked up.