2000 Pontiac Bonneville Oil Pressure Gauge/Meter All the Way to Max.
 

Problem I've been having with My 2000 Bonneville, The Oil Pressure Meter Started going all the way to Max whenever I turn on the ignition or even when the Car is Running, I don't visually see any oil leaks or Problem with My Engine Oil, Tranny, Or Brake Fluid. I'm thinking is the Oil Switch/Fuse. Could I Be Correct?, If I Am, Where is the Switch/Fuse Located?, If I'm not right, What Can I do to Rectify this Issue?
Thanks.

Sounds like the oil pressure sender has went bad, or the wiring may have a short, remove the passenger side wheel, and the splash guard so you can see the oil filter and area surrounding it, the sender should be above the oil filter.
https://www.gmforum.com/trouble-shoo...cation-284737/

I highly recommend going with an OE Ac Delco Sender as a replacement, inspect the wiring though, wiggle it a little where it plugs into the sender, and see if the dash gauge jumps, while doing so don't have the car running m just in the ON position.
If the wiring harness is dirty spray it with some contact cleaner to see if anything changes, if not replace the sender, they are pretty easy to remove, and you can do so without draining the oil if you can quickly thread the new one into the hole.

ACDELCO Part # 2131650 should be the replacement sender you need.

I agree with William E. It's a very common problem with the 3.8 engines, also make sure the power steering pump isn't leaking because I've seen the oil sender plug get saturated with power steering fluid.

Had this happen a couple of times on my Bonneville, and fixed it both times by replacing the oil pressure sender.

Its all Clean Under there, There is no Sign Of Leak Or anything.

Where is the Oil Pressure Sender Switch/Plug?
 

Well, I looked for the Oil Pressure Sender Switch/Plug On the Passenger Side As Directed, I couldn't find it, the Oil Filter (Which By the Way is Located Further inside the Engine area, & Harder to Reach From The Passenger side tire area). Access/View Of the Oil Filter is Blocked by the Body Panel. They only side covered by the Splash Guard is the Front/Right Side (i.e Facing the Passenger Side Tire) But the Oil Filter is in the Left Side Way Inside, I Did Oil Change, The only way I could get to the Oil Filter is From Under the Car. I Took Some Pictures. Check'em Out...

if you feel above the oil filter, you will feel a pigtail going into what feels like a giant nut. its 7/8" if i remember correctly. you will need a large open end to remove it. i can almost guarantee that is you're problem.

Where is the Oil Pressure Sender Switch/Plug?
 

Well See, In that Picture, That's how the Oil filter in My Impala Sits, Sort of Facing downwards. But in My Bonneville, Its Attached Sideways, i.e Horizontally (Not Downwards like in that Pic), The Side/Area where the Oil Filter is is Blocked by the Body Panel, Its not Possible to get to, The Oil Filter is Sort of to the Left & Further Underneath the car (i.e if You're Facing the Passenger tire area), but the plastic Splash Guard is to the Right/Front of the Car. I don't know if You guys understand what I'm trying to describe?, The last time I tried to upload some pics but the site wouldn't let Me, (I Just figured out Why, the Pics were too Large, Had to Re-size the Pic, :p) So I Just Uploaded them so You can better understand what I'm trying to say guys.. See how My Oil Filter is Positioned?, I don't think the Oil Filter can be Reached from the Tire area Or even get to the top of Oil filter for that matter :).

it should be someplace near the filter, my guess is more toward the wheel well and up. if you get a flashlight down there, there should be very few wires in that area. if you trace the wiring, you will end up at the oil pressure sensor. sorry i cant be of more help.

here is a video i found for the other style oil filter setup. i cant imagine the sensor would be very far away from there on you're car.



you might end up having to remove the oil filter to get at youre's. i did mine when i was doing an oil change and got away with removing it from under the car while the filter was off. completely avoided removing the wheel.