Red security light on dash

[Laraby]

My 03 ram has a red light on when key out of ignition and I have no dome lights
With key on all works except radio have swapped radios and changed ignition switch and cylinder no change
Any ideas

 

[TheSatinPumpkin]

strange. i only get the red light flashing when my battery is on the way out, when i turn the key.

 

[HemiLonestar]

Does it start? I had this issue (I don't have security installed) when my battery was crapping out.