Chevy Cummins Oil Pressure Issue

[jsavage977]

I have a 96 Cummins 12 valve 215 p7100 6bt sourced from a dodge 2500. Swapping into a 1988 gmc v3500. Im rounding up all the small things now but I cant seem to get my oil pressure gauge to work. I'm using a new chevy OP6640SB oil pressure sender in the stock cummins location where I took out the dodge two wire oil pressure sender. If you need pics you can check out my build thread.
http://www.rme4x4.com/showthread.php...-warrior/page2

The problem is that the oil pressure gauge is always buried at 3 o'clock weather the key is on or off, the engine is running or not. Always at 3:00. I tried to test the gauge itself by pulling off the wire that goes to the sender and grounding it. This puts the needle dead on at 0psi with the key on. I am baffled about why this is not working. I also have a extra gauge I tried but it does the exact same thing. Exactly 3:00.
Is it possible for a brand new oil pressure sender to be 100% broken?
Any help on this is very very much appreciated!!!!