I'm having issues with electrical on my 4runner. It started earlier this week. I went to start my truck after work, I lost all power when I turned the key to start it. After shutting it off and turning back on, it started again and all was well.

Today I can't start it at all. Turning headlights on results in a loss of any electricals anywhere in the vehicle. I have power and dash lights with the key "on" until I either go to crank it or turn headlights on, after which it instantly loses power again.

With the key on, I have full power to the windows, brake lights, interior lights, and horn. I've tried a different battery as well so I know that isn't the issue.

Does this sound like a shorted wire or a bad ground? I have very poor knowledge of electrical, no idea where to start here

 

It sounds like you need to get up to speed on simple DC circuits

A Multimeter is your friend .

Without real voltage numbers your just guessing

Always start at the source of power .

Battery voltage at least 12 vdc or slightly higher with the engine off.

Terminals clean and tight not broken .

Does not hurt to pull the grounds off and clean the lugs and the attaching hardware .

Shorts are a direct path to ground will cause circuit protection to open or a melted wire till it melts enough to open.

A fire if anything flammable is close enough.

 

still sounds like a battery connection, likely to the main engine fuse block by the battery. i would start by cleaning the battery connections up.