Electrical issues

Howdy,
I have a 99 taco, V6 4x4 manual. Bought it 500 miles ago, @ 226k miles. She runs like a champ but I have (I hope minor) electrical issues I'd like to troubleshoot.

-When I turn the key to on without cranking, the radio (aftermarket) is usually on, but when I crank it may or may not come on; but then when driving it may randomly come on if it was off.
-In addition, the windows have been working lately but they sometimes do the same thing, won't work after first cranking but might work later on while driving.
-Cruise control will turn on but won't set (not sure if related to windows and radio)
-just noticed one of my parking lights often starts turned off but might turn on if I tap the cover. I think this may be a bad connector though, probably unrelated to radio and windows. (I changed the bulb)
-open passenger door (with truck off) and the interior lights do not come on immediately, may turn on randomly (thinking this could be unrelated too)

While I *think* those last 3 may be unrelated to the first 2, I suppose they could be related since they're all electrical issues, so I listed them anyways. Do I have maybe a grounding wire issue somewhere? Or perhaps a loose wire? Could a corroded bulb connector cause these other electrical issues? I'm a DIY-er, but have very little experience in vehicle electronics so thought I'd come ask TW! TIA!

 

Location would help as I would ask, was the truck purchased from a flooded area?

 

02hilux - I purchased from someone in San Antonio TX, and live in central TX myself, not particularly flood prone. He was 3rd owner, but I'm pretty sure all owners before me were in San Antonio.

That being said, it does seem like one of the owners might have gone off-roading with it at one point, so who knows if they went through a riverbed or something

 

The headlight issue will not affect the other two. Might help if you remove the plastic door trim along the floor board and see if perhaps the PO screw the retaining tabs/screws into there electrical wiring there.

Sorry, can’t be much help.