Had a similar experience (other then what you did with your instrument cluster) for me it was after I did an oil change. Just bought the truck, wanted to change all the fluids and filters. From reading posts on here I used all International filters (same manufacturer as ford filters but less then half the cost). Turns out I had an aftermarket napa filter and cap. Nothing seems out of the ordinary doing the oil filter change as the cap seemed the same as my 6.0, filter snapped in, screwed all the way down back into the canister and after starting the truck up, the low oil pressure light only stayed on a second or two as they oil system was being charged up. Due to the dimentional differences between aftermarket and OEM oil caps, the spring loaded drain valve didn't have enough pressure to remain seated, so it acted as a filter bypass and would go right back into the oil pan. It took a few hundred miles after the filter change before the low oil pressure light would come on during startup, and even then would only stay on for a matter of 2-3 seconds but was enough to warrant investigation. Luckily a quick search found others on the forums have run into this problem before. Ordered a new cap for $30 from ford and all has been well since.
Sorry for the ramble, probably included a little too much detail. I hope your able to find a simple solution such as I did.