GMC Repair: 99 GMC Safari, gmc safari, turn signals

Question
Sometimes the instrument cluster in my van does not register. All of the guages go either all the way to the left or all the way to the right and my brake lights and turn signals do not work. Then after a while they come back online. Why and what can I (and by me I mean my mechanically inclined husband who has no idea I'm doing this) do about it?

Answer
Hi
I see one common item, G105 (Ground circuit 105)  which terminates (or grounds) at the Thermostat Housing on top of engine.
Other than that I do not see any other common wire or harnesses.
I hope this helps
If more helps is needed, please follow post back
Good luck
Pawl