Dash lights work when they want, any ideas?

[walkerb]

Here’s the issue. It’s a 74 custom and what’s happening is the cluster lights only seem to work when they (lights) get warm or the switch has been on for a while.
When they work or come on they stay on but not until I’ve had the headlights on for a little. The light for the heater switch comes on and is lit as it should but the cluster lights do what they want.
I haven’t taken the cluster out and I don’t have any experience with ( in printed boards/circuits?) on the back.
I don’t like the fact that I have to use my cell phone to see my gauges early in the morning. And there’s also the fact that it’s just not right!
Any ideas on where to start or anyone else have or had this issue? I’ve gone over grounds and wiggled wires with no change. Also doesn’t help that when I’m doing all of this its day time and really frecken hard to see any lights!
I included a pic of the truck because everyone, including me, loves seeing pics.