Aftermarket oil pressure gauge not working

[ttravis88t]

(1997 Eclipse GST 7 bolt) Hello, so I have an aftermarket oil pressure gauge hooked up to a gauge pillar. The other day, I was experiencing weird oil pressure numbers and since the car was running fine, I assumed I had a bad ground or maybe a bad power wire that would be throwing off the readings near the sending unit (I’ve heard this is a common thing.) so I disconnected the power line for the sending unit that wires into the car and took some excess wiring to hook it directly to my battery to test and see if that would cause any change in the numbers. Well, I started the car and the gauge doesn’t work, it powers on, but it just sits at 100. Anyone have any ideas?

 

[1990TSIAWDTALON]

Check the wiring going to the sending unit. It may be grounded somewhere, giving you a maximum reading.

 

[mattp_65]

Or it could be a bad sending unit