Temp gauge and other dash probs

1985 Ram 50. 101K+ The motor is stripped down to basics. It ran well and everything on the dash worked properly when I bought it 13 years ago. Only use it to haul stuff and when my primary rig is down.
I removed the dash and cluster to replace the OD cable a long time ago and since then I get intermittent gas gauge failure, intermittent turn signal failure but the temp gauge always worked. Oh yeah I never got the column covers back on tight. I think I've lost a couple screws for that.

check that all the connections are tight.