Instrument Cluster Not Lighting Up... Puzzled
Thread Starter
Safety Car
Joined: Sep 2007
Posts: 3,816
Likes: 16
From: Anchorage Alaska
St. Jude Donor '08-'09-'10
Instrument Cluster Not Lighting Up... Puzzled
Hi guys,
Curious problem I have here. Yesterday I turned on the headlights... they popped up and illuminated like they should; however the instrument cluster did not. I cycled the headlights and no change. Thanks to the HUD I didn't have much difficulty driving home at all, but I'd like to know what might be causing this.
When I got home, I shut off the car and THEN the instruments illuminated. I then turned off the headlights and they dimmed as they should. Turned the headlights on again and everything worked.
The day before, the same thing happened as I started the car and drove home in the dark. Except that time, the instrument cluster illuminated on its own about 3 minutes later.
At all times, the DIC works perfectly. All the gauges work perfectly. They just don't always light up with the headlights.
Thinking back, I don't recall if the HVAC/radio was illuminating or not. The dimmer adjust **** had no effect on anything whatsoever.
any ideas are appreciated!
Curious problem I have here. Yesterday I turned on the headlights... they popped up and illuminated like they should; however the instrument cluster did not. I cycled the headlights and no change. Thanks to the HUD I didn't have much difficulty driving home at all, but I'd like to know what might be causing this.
When I got home, I shut off the car and THEN the instruments illuminated. I then turned off the headlights and they dimmed as they should. Turned the headlights on again and everything worked.
The day before, the same thing happened as I started the car and drove home in the dark. Except that time, the instrument cluster illuminated on its own about 3 minutes later.
At all times, the DIC works perfectly. All the gauges work perfectly. They just don't always light up with the headlights.
Thinking back, I don't recall if the HVAC/radio was illuminating or not. The dimmer adjust **** had no effect on anything whatsoever.
any ideas are appreciated!
Le Mans Master
Joined: May 2006
Posts: 5,987
Likes: 18
From: DuBois PA
St. Jude Donor '11-'12-'13-'14-'15
They are actually UV Blacklight tubes in the front of the gauges. The power supply could be going on em but I'd suspect the dimmer or a loose connection on the back of the IPC first.
The green connectors feed the UV tube's power supply:
The green connectors feed the UV tube's power supply:
Thread Starter
Safety Car
Joined: Sep 2007
Posts: 3,816
Likes: 16
From: Anchorage Alaska
St. Jude Donor '08-'09-'10
Tim, Thanks for that info. I think after work today, if I can find time, I'll remove the cluster and check for loose wires. That would be nice if that's all it was.
If the wires turn out to be OK and my suspicion turns to the UV power supply, is that part replaceable or would buying another full panel be the only way? Is there a way to test that power supply that anyone knows of?
Thanks!
If the wires turn out to be OK and my suspicion turns to the UV power supply, is that part replaceable or would buying another full panel be the only way? Is there a way to test that power supply that anyone knows of?
Thanks!
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
GM does not sell the power supply seperately. You would have to buy the whole cluster. I have an extra cluster for a '99 with hud if you find you need one. I've never installed it. I bought it from ebay just in case the power supply ever failed, which it never has.
Le Mans Master
Joined: May 2006
Posts: 5,987
Likes: 18
From: DuBois PA
St. Jude Donor '11-'12-'13-'14-'15
I have a spare light circuit I'm saving as well, I sent my spare IPC to Speedhut to be used as a test mule for Custom Gauge Face Plates. (cool stuff!!!!!!!)
I''ve actually never heard of one going bad yet, but you should be able to check the output with piercing probes.
I believe the Gauge's dimming and lighting is an internal function of the IPC and not controlled by the BCM. Let me check because, like you alluded to I think the HVAC is also controlled by the IPC... if it's acting up that's a great indicator to troubleshoot by.
Tim
I''ve actually never heard of one going bad yet, but you should be able to check the output with piercing probes.
I believe the Gauge's dimming and lighting is an internal function of the IPC and not controlled by the BCM. Let me check because, like you alluded to I think the HVAC is also controlled by the IPC... if it's acting up that's a great indicator to troubleshoot by.
Tim
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
I think the BCM does indeed control the illumination however its source of brightness comes from two different locations. During the day, the brightness of the DIC and HVAC is controlled by the light sensor in to the top of the DIC controller at the right side of the cluster. The light sensor on top of the dash determines when to switch to the night mode. At that time, the dimmer slider in the HUD controller runs the brightness commands to the BCM. The BCM outputs via a variable analog signal that sets the brightness.
So with all that said, check your brightness during the day by covering and uncovering the DIC sensor and see if the DIC and HVAC displays dim and brighten normally. At night, run the dimmer up and down. If that works normally and this is an intermittent problem, does it happen only during the day or only at night. If both, then I would be looking at the BCM connectors. If during the night only, then the DIC controller's dimmer is probably bad or the connections to the cluster.
So with all that said, check your brightness during the day by covering and uncovering the DIC sensor and see if the DIC and HVAC displays dim and brighten normally. At night, run the dimmer up and down. If that works normally and this is an intermittent problem, does it happen only during the day or only at night. If both, then I would be looking at the BCM connectors. If during the night only, then the DIC controller's dimmer is probably bad or the connections to the cluster.
