98 Grand Prix interior lights dimming

[PurpleGuy]

The interior lights dim and eventually cutout in my 98. Lights include the gauges, dual digi hvac, headlight switch, HUD switch and all of the door switch lights.

When you first get in the car at night they're nice and bright like they should be. Slowly over the course ~30min they'll slowly dim and eventually shutoff all together. Radio lights work fine all the time. The dome lights and all external lights work fine.

Thoughts?

Thanks

[PurpleGuy]

Bump

[Scottydoggs]

check the ground wires on the trans bell housing bolt, where the neg bat cable is.

[PurpleGuy]

I've checked that once before when I had a problem with the car losing power. It was fine last time I checked. I would think if that ground was having a problem the whole car would have a problem. Not just the interior lights

[Scottydoggs]

seen a bad ground cause the lights to act up before, and lose power. its a free check.

[PurpleGuy]

Grounds on the trans seem fine from what I can tell. I didnt breakout a multimeter and do a continuity test or anything like that. I noticed a couple nights ago that the dic lights would flash with the blinker. Only did it a couple times though. Didn't do it the whole time I drove it

[PurpleGuy]

Is there a ground by the parking brake?

[PurpleGuy]

Bump

[Bronco Boy]

Seeing as how the BCM controls all these items, maybe it if fubar'd? Grasping at straws here. LOL

[PurpleGuy]

Not sure Bronco but I do have an update. The DIC died about a week ago. I replaced it today. The old dic would constantly flash and flicker when the lights would dim and would eventually cutout. New dic doesn't do this. Also the new dic doesn't blink with the blinker like the old one did.

[PurpleGuy]

Got this taken care off. Replaced the headlight/dimmer switch yesterday and the car was fine driving over an hour with the lights on last night

[Bronco Boy]

Interesting. Glad you figured it out.

[PurpleGuy]

It is interesting. Never seen a dimmer switch cause this issue. Only reason I replaced it is the other night I was playin with the switch and the dic would go full brightness like it was daylight and the lights were off. Screen went full brightness and all of the button lights shut off. Dual digi was goin wacko too. Threw a junkyard switch in and it's been fine since.