Electronics randomly not working - NEED HELP!

[scoobopdan]

So I had a thread going from the other week - http://www.yarisworld.com/forums/showthread.php?t=55721 . It was about how my vent fan has seemingly began to stop working. Some start ups it will be fine, some times it won't work but will randomly turn on in the middle of the drive. The other night a swift punch to the dash seemed to be enough to make it work. Now, my dome light stopped working. I thought that somehow the bulb blew or something and that I should change it. The next day I noticed that it was working. Last night it wasn't. Today it is. I have no idea if the problems are correlated but I can't help but wonder if the random not working is too coincidental. And if they are correlated then I have to assume, given how things have been working, that the problem is only going to get worse. I've never experienced something like this before and have no idea where to start looking, someone pplleeease help!

[CTScott]

Have you owned your car since it was new? It almost sounds like it has taken a bath at some point and is now suffering from corroded connections.

[WeeYari]

^ Used. He bought it last year. I would also suspect it has had a questionable past.

[bairjo]

is this your car?
https://www.youtube.com/watch?v=JKgT4z7gasI

[scoobopdan]

is this your car?
https://www.youtube.com/watch?v=JKgT4z7gasI

Haha no thank god. I'm not sure what exactly I would be looking for in that case, but I know at least when I've changed the plugs, put a new COI on it and general maintenance, it doesn't seem like it had water damage. Yes I bought it used and yes there are some things that make me wonder (Like there's a weird pinch in the metal of the driver door) but nothing that makes me connect the two. A while ago I was having issues with starting, eventually we decided on the starter (a mechanic confirmed it) but could it maybe still be the battery too?

[NYC-SE]

I doubt its the battery. Like CTScott mentioned this seems more like a connection issue. If it's working/not working/working again that sounds like a loose wire somewhere making intermittent contact. Could be the power supply or the ground wire. Things like this are usually a royal pain to chase down. Good luck.