Welcome. I will try my best to help you and in order to do that, I need you to describe as best you can because I only know as much about your problem as you have told me in your post, so my answer will be based on what you have posted. Please feel free to reply as needed.
Let try some testing. Take the switch out and find the white wire in terminal M. Ground this terminal and see if the lights turn on.
I tested the white wire to ground as part of the override switch test. When the override switch is in the ON positiion the white wire is connected to ground. When in the OFF position it is opn to ground. I did not check this with power on.
The concern is that the courtesy lamps do not go off so I have to remove the fuse to keep the battery from running down. Plus when I turn the dimmer switch to full on, the courtesy lights get brighter but the dome lights do not come on.
OK, lets tryt he diagnosis below.
DEFINITION: Use this diagnostic in order to diagnose the Dome and/or Courtesy Lamps Always On with all vehicle doors closed and the dome lamp switch in the OFF position. On vehicles equipped with remote keyless entry or an interior lamp control module will cause the interior lamps to remain in the ON position after the door is opened for approximately 40 seconds or until an ignition ON cycle has occurred.
Did you perform the Interior Lamps System Check?
Go to Step 2
Go to Interior Lamps System Check
Do the courtesy and/or dome lamps turn OFF?
Go to Step 3
Go to Step 7
Is there continuity?
Go to Step 5
Go to Step 6
Is the vehicle a suburban/utility with cargo doors?
Go to Step 12
Is the repair complete?
Replace the headlamp and the panel dimmer switches.
Disconnect the interior lamp control module or the keyless entry module.
Go to Step 8
Go to Step 11
Connect a J 39200 , set on Ohms, between CKT 157 (GRY) at cavity B of the interior lamp control or cavity K of the keyless entry module and ground.
Go to Step 9
Go to Step 10
Repair the short to ground in CKT 157 (GRY) between the headlamp and the panel dimmer switch and wither the interior lamp control module or the keyless entry module.
Replace the interior lamp control module or the keyless entry module.
Repair the short to ground in CKT 156 (WHT) between the headlamp and the panel dimmer switch and the dome and/or courtesy lamps, the interior lamp control module or the keyless entry module.
With a J 39200 still connected at the headlamp and the panel dimmer switch cavity L and ground, disconnect the door lock control module.
Is there still continuity?
Go to Step 13
Connect a J 39200 , set on Ohms, between the door lock control module connector cavity F and ground.
Go to Step 14
Go to Step 15
Replace the door lock control module.
It is separate. It is under the left side of the dash by the remote control door module. It is #2 and the remote control module is #3
Is there a place to get an actual schematic for this circuit?