Sometimes I may not drive the car for a month or two and after a few weeks the battery goes dead from all the onboard electronics these cars have. Even a solar charger hasn't worked to keep the battery charged. I was going to add a battery disconnect switch but then I noticed this big wire with a connector going into the + battery terminal: I pulled it out and all power to the car was disconnected and when I plugged it back in, the clock still showed the correct time. So what does this wire do? If I disconnect it would it prevent the battery from running down from all the electronics onboard? I still plan to keep the solar charger connected. If the clock still showed correct time, something must still be connected.
This is a Classic Prius? You didn't specify but it's in the Gen I forum so I'm assuming so. I can't directly answer your question, but would suggest that you pull the DOME fuse if you want to disconnect the 12V system. Alternatively try a float charger.
Yep its a Classic which is why I posted it here. What is a DOME fuse and where would I find it? I don't have electricity where it's parked so I can't use a float charger, thats why I use a solar charger.
Gotcha on the electricity thing. FWIW, please update the info in your avatar with your car info, it helps as many times people inadvertantly post in the wrong forum--I did it myself the other day--and it just makes things clearer. The dome fuse should be under the hood in the main fuse box, but I'm not familiar enough with the Classic to tell you exactly where it is. Someone will chime in soon though.
Since you don't mind disconnecting the large cable, I suggest you also disconnect the small "sense" wire which is also attached to the + battery terminal. Then all power will be cut off. If you leave the power off for a while, you will find the clock eventually will lose the correct time.
OK so the DOME fuse you mention is the dome light fuse. What will removing that fuse do? The dome light is off when the doors are closed anyway so it doesn't run down the battery when the car sits. Anyway, I parked it and pulled that fat wire from the battery terminal. We'll see in a few weeks.
The dome fuse is more than just the light, it seems to cut off all accessory power. The vehicles are shipped from Japan with the DOME fuse out and are put back in by the Port or the dealer (I'm not sure which actually) and then all things need to be reset. I just think that would involve fewer sparks and less hassle than disconnecting the battery cables, but either will do the job.
