My 2004 4Runner is having some electrical issues and I'm wondering if anyone else has seen this.

Last week, I had it sitting for 3 or 4 days and it seemed completely dead when I tried to start it. No lights, no crank, nothing. I thought maybe I had left a light on, so I hooked up some jumper cables and within 10 seconds it had started. No lights were on though. I didn't have any more problems until yesterday.

My wife got in it and it seemed like the battery was dead again. She sat in it for a while and I guess tried turning it on a few times and eventually the lights came back on and it started right up.

Then she got home and had me come outside because the key fob wouldn't unlock the doors and all the lights were off again. She reached through the drivers door to unlock the back door and I crawled in to grab some bags out of the trunk. After I got out, the light on the driver door came back on and it seemed like everything was working again.

Has anyone had this happen? My plan is to look for dirty or loose ground connections and check all the relays in the fuse box in the engine bay.

It seems like the C/OPN relay might be the most likely culprit if a relay is the cause, but if anyone has experienced this I would like to hear how you solved it. **Edit to add I looked into the C/OPN relay again and it seems like that's only for powering the fuel pump, so probably not the culprit here**

Follow up (I hate when people don't post solutions). The positive cable on the battery wasn't tightened down all the way. Luckily it only took me about 5 minutes of poking around in the fuse box to think about checking the battery connections. As soon as I tightened it the power clicked back on and it's good now.