High Oil Pressure

I noticed my oil pressure gauge going up to 80 psi. It has never done that before. It was time for an oil change and after that was done, the pressure gauge stayed the same. Whats going on here? Is it my sending unit bad gauge. The check gauges light doesnt come on. I dont know if this helps but, when I turn the ignition in the aux position, the gauge goes to 80psi as well without even starting the car.
Any ideas?
--Thanks

Let me add some info: 2000 Jeep Cherokee. 2WD. 4.0L.

Take the sender wire off...it should read zero.

If it is still high...it is wiring or the gage set has a problem.

What year? Some years have a problem at the instrument pack connector.

Its a 2000 Cherokee Limited, 4.0L, 2WD, 4DR. What are possible solutions?

Did you try taking the wire off yet?

Here is some previous posts.....just do a search...
http://www.automotiveforums.com/vbulletin/showthread.php?t=547390&highlight=instruments

http://www.automotiveforums.com/vbulletin/showthread.php?t=239434&highlight=instruments

FIXED!!! It was the sending unit like I thought. Thanks for your help, AlohaBra.

As I was reading about your original problem, I was going to say it was the sending unit because I just had that problem last week. I had gotten my oil changed and then the next day my oil pressure gage shot up to 80. Freaked me out. Weird.
Glad you figured it out.