Shortly after beginning to drive the truck all the warning lights on the dashboard come on (ABS, Check Engine, AirBag, etc.) and all gauges stop working (Speedometer, Gas gauge, Temp., etc.). This is a giant pain in the A(*! Do you know the fix for this? Have been told it MAY be an ignition wiring harness problem. Any advice would be greatly appreciated!

I had just bought the truck and everything was good. After a few weeks of driving my check gauges light started coming on. But it only does it when i am slowing down or at a stop. My oil pressure drops to nothing but when i step on the gas the light goes off and pressure jumps up to normal...i don't know what the heck is wrong with it.