neewbie needs help with electrical problems

[larryforce]

I purchased a 91 grand prix gtp a couple of weeks ago and am having a couple of small problems. My fuel light and check gauges light were stuck on, but after following the directions and resoldering my instument cluster that problem is solved. what continues to plague me is my heads up display always reads 0 mph and my dic still says ceck fuel level/ shows 0.0 mpg. Oh yeah the dic also only comes on ocasionally/ flashes on/off sporaticly.
thanks for any help as I have no idea where to start.