Engine gauges

Looking for some help chasing down some engine gauge gremlins. I have twin Ford Lehman 120HPs on my Cheer Men PT 41 trawler. I have attached two pictures one at the lower helm (both RPMs ~900) and one at the upper (port RPM~900, Stbd 150).

Lower Helm:
RPMs seem accurate
Amps seem accurate
Water Temp usually read about 185deg on both
Oil Press reads ~58 port and pegs to the far right on stbd

Upper Helm:
Port RPM seems accurate and consistent with lower, stbd does not move.
Amps seem accurate
Water Temp on port seems accurate, stbd pegs to far right
Oil Press reads ~58 port and pegs to the far left on stbd (opposite the lower helm)

Any suggestions on where to start looking? Do the terminals on the actual gauges need cleaning/sanding? Where on the engine would I be looking? Let me know if I missed anything. Thanks in advance!

-Donny

Donny, You need to check each connections to be sure nothing is loose and look for corrosion. I would recommend that all gauges have a separate ground wire leading to a common buss. You need to look at the connections on both ends. This does appear to be a ground problem. Chuck

Can you easily swap gages to see if the problem follows the gage?

FlyWright,
I might be able to try that when I take things apart to clean all of the connections as Chuck suggested. Thanks!

-Donny