My mom's car had syptoms vaguely similar to yours. The gas gauge, temperature guage, turn signals and the radio would work intermittently.
I thought it was a loose wire or ground, but one of my dad's friend came over and changed the fuse and now it works fine.
The fuse was burnt at the edges contacting the terminals, and not at the usual place in the middle of the fuse --- that's why I missed it.
It may or may not fix your problem, but it's worth a try. The fuse is only $0.50cents.
Good luck,
jrmd01@yahoo.com