Please Help

My boyfriend is having alot of problems with his
truck.
We need help figuring out where the problem really
lies.
1). The dashboard lights sometimes all light up
and when it wants to sct up the oil level gauge will
be the only one not lighting up.
2). There was some screetching coming from the
back end of the truck, like from the back wheels.
He has all four new roders, he thought maybe it
was him needing new wheel bearings???
3). Sometimes in the summer time every now and
then the driver side would blow out hot hair when
we turned the a/c on, and the passenger side
would be fine blowing out the a/c, and it would
continue to do this until he was to turn off the truck
and turn it back on to reset the stuff.
4). And something that jus recently started today
that has me really scared is the wiring in his door
must be messed up because his heat warning deal
went out on his truck along time but now all of a
sudden it makes a clicking noise that indicates it
kicking on and off and so it does this at least once
every 5 minutes, maybe even more.
And lastly I think,
5). Everytime he turns left it beeps alerting us, and
dashboard says "Service Brake System".