Security light on and overhead console is crazy!

[Angrybird12]

I bought this 99 Astro LS on Saturday and have discovered a couple issues.
First is the Security light is on and stays on all the time but the van runs normally.
Secondly the overhead console info center is bonkers. The compass just changes direction ocassionally by it'self even if you don't change directions. The Temperature sometimes freezes and will not change with the outside temperature (usually just shows the temperature at last startup) The trip info is all over the place, the average economy will jump around and the instant economy hardly changes from 6mpg. The gallons used will be different every time you start the van and may only change .1 or .2 gallons when the gas gauge goes down a full quarter tank.
I hooked up my OBD reader and opened the app on my phone that shows everything that the overhead console shows except the compass and temperature, according to it the mpg instant and average show like it should.

I noticed on the wiring diagram that the overhead console and the security system are tied into the same communication wire going to the ECM.

Does anyone have a clue to what may be going on, I have it narrowed to either a bad wire connection, bad ECM or bad overhead console electronics.

[Captn. Crunch]

Yikes! Ya sorry but I've got nothing to offer in the way of advice on this one. It sounds like your heading in the right direction so good luck. When you find it you can post the cure and we will all have learned something new