Well i have a 1989 chevy k1500 with about 150,000 miles on it. My check gauges light will come on and will occasionally; I noticed that my oil pressure gauge will drop to zero and then back up. I have oil in the truck (5w-30) mobile 1. When i purchased the truck the oil pressure gauge showed that there was good pressure and the truck ran very good I thought I would change it because it was due for a change. It still ran good after that. After getting my truck fixed a couple days ago because i couldn't start the truck; found out it was a bad ignition module.. I searched around to see what other people had to say and i found out that usually the oil pressure sensor will go bad or the instrument cluster will have a bad connection. I plan on taking the instrument cluster out because not all the bulbs light up the cluster so i think they need to be replaced, not only that but my shift indicator is also off.. Does anyone have any suggestions on where to start? Maybe cleaning the contacts on the instrument cluster first and fixing my shift indicator and see if that works. And then changing my oil pressure sender.. and then doing an oil change. I also dont know how to hook up a mechanical gauge to see if my pressure is good, but i think it is because it runs good.