For years, I've had a problem with my interior lights flashing, like mores code. Really bothers me at night. It is intermittent, does it all the time, sometimes, and months (even a year) not at all.

So many things it could be, each door has a door handle swich, could be the BCM, dimmer swich, short in a wire.

If I look into it, it will stop doing it (Once it blinked for a week. I took it to a shop blinking all the way. Left it for the day, when I cam back, they said they worked on it all day and couldn't get it to blink. Drove all the way home blinking).

I got my good old GM Service Manual and did the Interior Lamps Diagnosis.

Ignition Switch to RUN,
Press and hold the power unlock swich,
Cycle the Headlamps 6 times,
Release the Power Unlock Swich.

I pulled the front LH door open. Heard one Bong. Did each door, with a bong each time. I turned the headlights on, Bong.
I then turned the Interior Lamp on, no bong.

This took a total of about a minute. It was soooo cool, I did it again, with the same resluts.

I may have found it to be the Interior Lamp Control.

A couple years a go, the Dealer told me it would be a lot of money to do an electrical diagnostics. "They would have to get in and check a bunch of wires. Electrical stuff gets real expensive, quick." Took me about a minute.

This GM Diagnosis is GREAT!!!

Maybe I should wait until after I put the part in to post, since it might not fix the problem like it should?

Chris.

Are you talking about the Interior dimmer / lamp switch?

Basic issue missing here, what year is the car?

Yes.
1997.