Simple/Weird gauge question....
 

I hooked up a new set of gauges to replace originals that were on their last legs Some worked when you tapped them some were just dead. On the new gauges (analog) all of the starboard gauges are reading low.....IE Low oil pressure (30), Low water temp (135), Low Voltage (12). Port engine gauges are reading correct values. I didnt pick up on the common theme (all starboard gauges) until I checked the temps with digital thermometer, voltage with a multimeter etc. Thats when the light bulb went off. Im stumped

Normally aspirated 1998 502 Mag PMI's

Edit: Found this older thread here and gives me food for thought.
https://www.offshoreonly.com/forums/general-q/256431-port-gauges-read-low.html

Edit #2 There is a rheostat dimmer. Not sure if that is a piece of the puzzle or not.

Update. There was a kinked wire just behind the starter. Fixed it and all appears to be good. Ill test it out on Sat.