2005 Cadillac CTS 3.6L

Wild Bill

Sr. Member
Joined
Oct 31, 2010
Messages
202
Points
18
Make
Cadillac
Model
CTS
Year
2005
Miles
110,000
Engine
3.6
When headlights are on instrument lights are not visible. Instrument light rehostat functions normally with headlights off.
 

grcauto

wrench
Joined
May 29, 2014
Messages
1,456
Points
48
Isn't this normal?
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,932
Points
63
Is this a new situation, or did you acquire it this way? Dimming the panel lights when the heads are on seems to be pretty common, so maybe this is "normal".

You can find schematics for this system at <charm.li> I took a peek, it is far more complicated than I feel is justified for an automobile. I am reluctant to get into it. Not "refusing", but very reluctant. I hope somebody else will join in here...
 

jigfeett

Hero Member
Joined
May 30, 2008
Messages
453
Points
18
Location
Pacific Northwest
Are you saying driving at night in the dark that the dash is totally dark and cannot be brightened to see any gauges at all?
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,932
Points
63
No, I misunderstood! I thought you were saying the panel lights were too dim to see in daylight when the headlights are on. Still, though, is this a new situation, or a long-existing problem?
 

Wild Bill

Sr. Member
Joined
Oct 31, 2010
Messages
202
Points
18
Had the car for a year. At night the instruments are completely dark. Cannot see them at all. Since I retired no longer have access to good diagrams.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,932
Points
63
I must not be asking clearly enough, will try again... have these lights ever worked differently in the time (~year) you have had the car?

Go to <charm.li> for the schematics
 

grcauto

wrench
Joined
May 29, 2014
Messages
1,456
Points
48
I found it quick. It's controlled by a chip in the cluster. That small long rectangle of dashes is a chip that controls those devices including the lighting control.
A scan tool that can read the IP module to see what's going on would be nice. The chip may be bad requiring a new cluster.

charm.png
 

Wild Bill

Sr. Member
Joined
Oct 31, 2010
Messages
202
Points
18
I must not be asking clearly enough, will try again... have these lights ever worked differently in the time (~year) you have had the car?

Go to <charm.li> for the schematics
No, been like this since I got it.
 

Wild Bill

Sr. Member
Joined
Oct 31, 2010
Messages
202
Points
18
No, I misunderstood! I thought you were saying the panel lights were too dim to see in daylight when the headlights are on. Still, though, is this a new situation, or a long-existing problem?
Both day and night, been like this since I inherited it a year ago.
 
Top