Oil pressure gauge not working

[Bitsta]

Hey guys, I've got a ae82 bigport in my ae86. Just wondering why my oil pressure gauge isn't reading. When I start the car the gauge flicks all the way up, then it slowly declines and sit back to where it started. The guage doesn't move at all either when you drive it, only upon start ups. It's wired into a jdm ae86 cluster, but I'm sure something else has to be faulty cos it flicks all the way up when started.
Help me out please !

[Skylar]

Get a 4ac oil pressure sender.

Generally you want match the dash to the sensors it reads from. AE82 and AE86 don't have the same style oil pressure display. One has a light, the other has a gauge. You can swap light type but gauge types have to have matching sender and dash. In saying that a 7m oil pressure sender and a 4a one are probably the same.

[Matt]

You can buy tridon ones new off ebay

[Bitsta]

I wonder is its just the sensor playing up, cos the gauge does move upon start up

[Matt]

It's the sensor ae82 has the on/off switch where as the ae86 the actual gauge. The sensor in the link above is much larger than the one you have on your car.

This comes up all the time, especially when people use an engine out of an ae82

[Bitsta]

How would it read if I get that sensor ? Would it move up upon more pressure or would it still be an on/off

[Matt]

It'd read perfectly up/ down

[Bitsta]

Thanks man !