I would find the dash ground and inspect it. I had many of the same problems and many more and all it was was the dash ground under the dash down by my knees was a little rusty dirty. Once cleaned all of my lights worked and my gauges stopped acting crazy, etc. Give it a check its usually under the knee protector areas of the dash. Good Luck,
"That's awesome advice. Anytime I have a difficult repair, I fix something else that's much easier to get to. This one time, there was a hole in the oil pan so I replaced the side mirror on the driver's door."
Wanted: Tuffy rear underseat drawer. PM me if you have one.