oil pressure

Hi guys, Im new here. Great forum. I gots a question or 2. I just bought an 84 Chevy K/10 with a 350 engine. Everything on this baby works but the oil pressure guage. I dont know that much about this part of the engine. So my question is where do I start looking for the problem? Is it the sending unit or the guage,or the wiring? Is there a good way to know this? The guage is resting in max position. Is there a good way to check these components. I have a good meter. I just need to know what to look for. Any help you guys could give me would be greatly appreciated. Thanks again for a great wealth of info here.
Michael