Dome light random on/stuck on 09 HHR LT
Thread Starter
New Member
Joined: 08-04-2021
Posts: 29
From: MI
Dome light random on/stuck on 09 HHR LT
Howdy.
Last summer (with lots of help here) I resuscitated a 09 HHR LT with 2.4L that had been sitting for 3 years. I posted about it here: https://www.chevyhhr.net/forums/prob...g-3-yrs-64658/
When I got the vehicle from my dad, he'd pulled the dome light fuse to keep the car from from killing the battery. He didn't care for a dome light and drove it like that until he parked it for 3 yrs. After I got the car, I did some research and 'thought' the RAP relay controlled them and swapped the RAP relay. When I put the fuse back in, everything seemed fine and I thought I'd fixed it.
But after about a year of driving the car, the dome light has come on intermittently, and sometimes after turning the car off and leaving it the dome light stays on and doesn't turn off. I've resorted to pulling he fuse after waiting more than 5 minutes for them to extinguish.
I'm confident the doors are closed and it's not a door switch turning them on (the vehicle doesn't display any open doors when the lights pop on randomly so I don't think the BCM is turning them on due to a false open door signal).
More research seems to show an internal relay to the BCM is what activates these lights (like when you turn the vehicle off, the dome lights come on because the BCM closes an internal relay). It seems The RAP relay does radios and other stuff but not the lights... I suspect whatever relay turns the dome light on after turning the car off is sticking on, and randomly closing and that is what is turning the lights on randomly
My questions for the hive mind:
1. Is there such an internal relay in the BCM, or am I confused and its just the RAP relay near the BCM?
2. Has anyone else had this issue? Did you pull the BCM and replace the relay inside?
3. Are the BCM's programmed for specific years/vehicles? Can you pull any BCM from say any cobalt and put it in?
4. Do you have circuit diagrams to help trouble shoot this that you could post?
Thanks for your help and insight.
Tom
Last summer (with lots of help here) I resuscitated a 09 HHR LT with 2.4L that had been sitting for 3 years. I posted about it here: https://www.chevyhhr.net/forums/prob...g-3-yrs-64658/
When I got the vehicle from my dad, he'd pulled the dome light fuse to keep the car from from killing the battery. He didn't care for a dome light and drove it like that until he parked it for 3 yrs. After I got the car, I did some research and 'thought' the RAP relay controlled them and swapped the RAP relay. When I put the fuse back in, everything seemed fine and I thought I'd fixed it.
But after about a year of driving the car, the dome light has come on intermittently, and sometimes after turning the car off and leaving it the dome light stays on and doesn't turn off. I've resorted to pulling he fuse after waiting more than 5 minutes for them to extinguish.
I'm confident the doors are closed and it's not a door switch turning them on (the vehicle doesn't display any open doors when the lights pop on randomly so I don't think the BCM is turning them on due to a false open door signal).
More research seems to show an internal relay to the BCM is what activates these lights (like when you turn the vehicle off, the dome lights come on because the BCM closes an internal relay). It seems The RAP relay does radios and other stuff but not the lights... I suspect whatever relay turns the dome light on after turning the car off is sticking on, and randomly closing and that is what is turning the lights on randomly
My questions for the hive mind:
1. Is there such an internal relay in the BCM, or am I confused and its just the RAP relay near the BCM?
2. Has anyone else had this issue? Did you pull the BCM and replace the relay inside?
3. Are the BCM's programmed for specific years/vehicles? Can you pull any BCM from say any cobalt and put it in?
4. Do you have circuit diagrams to help trouble shoot this that you could post?
Thanks for your help and insight.
Tom
Last edited by top_prop; Jul 27, 2022 at 07:00 PM.
Moderator
Joined: 01-23-2009
Posts: 26,533
From: Fredericksburg,VA
The interior lights are not on the RAP. They dim out controlled by the BCM.
The switch in the dome lights is flimsy, they rarely last a few years.
Might be the dimmer switch in the dash board. All the way left turns them off.
There is an interior light relay that is on the PCB of the BCM, but it controls all of the dome lights. You have not specified which you are talking about. The map lights on the mirror, the map lights in the front, the dome light in the front, the cargo area light some models have a passenger seat dome light.
The DK BLUWHT wire comes from the relay to all of the overhead lights. The GRY wire goes to the BCM and through the dimmer switch to ground.
Don't start replacing the BCM, it is a much bigger job than you think. they are specific to your individual car (including the odometer reading).
The switch in the dome lights is flimsy, they rarely last a few years.
Might be the dimmer switch in the dash board. All the way left turns them off.
There is an interior light relay that is on the PCB of the BCM, but it controls all of the dome lights. You have not specified which you are talking about. The map lights on the mirror, the map lights in the front, the dome light in the front, the cargo area light some models have a passenger seat dome light.
The DK BLUWHT wire comes from the relay to all of the overhead lights. The GRY wire goes to the BCM and through the dimmer switch to ground.
Don't start replacing the BCM, it is a much bigger job than you think. they are specific to your individual car (including the odometer reading).
Thread Starter
New Member
Joined: 08-04-2021
Posts: 29
From: MI
DonBrew,
Thanks for the quick reply and insight on the RAP vs dome light relay on the BCM PCB.
To help clarify:
The car has three groups of dome lights and it's all three car controlled bulbs that come on. The push button bulbs in each dome light work just fine.
-front dome has three bubls: 2 push-button controlled lights & a car controlled dome/bulb
-middle has three bulbs: 2- push-button controlled bulbs & car controlled dome/bulb (between back seats)
- rear dome above the hatch controlled by car (single bulb).
the car doesn't have lights in the sun visors.
I just put the fuse back in: car controlled bulbs came on.... with all the doors closed. jiggled the dimmer switch and they went out. Opened the doors.. they came on... then closed the doors and the light faded like they should.
Will monitor and try to find time to replace the dimmer switch.
Thanks for the quick reply and insight on the RAP vs dome light relay on the BCM PCB.
To help clarify:
The car has three groups of dome lights and it's all three car controlled bulbs that come on. The push button bulbs in each dome light work just fine.
-front dome has three bubls: 2 push-button controlled lights & a car controlled dome/bulb
-middle has three bulbs: 2- push-button controlled bulbs & car controlled dome/bulb (between back seats)
- rear dome above the hatch controlled by car (single bulb).
the car doesn't have lights in the sun visors.
I just put the fuse back in: car controlled bulbs came on.... with all the doors closed. jiggled the dimmer switch and they went out. Opened the doors.. they came on... then closed the doors and the light faded like they should.
Will monitor and try to find time to replace the dimmer switch.
Last edited by top_prop; Jul 28, 2022 at 07:20 AM.
Administrator
Joined: 10-13-2011
Posts: 40,083
From: Welland,Ont Canada
Joined: 09-16-2022
Posts: 2
From: Titusville
My problem with my 2011 HHR was that the dome light and cargo light stayed on while engine was running. If engine was turned off and I exited the car after 5 minutes the light would go off. Door switches had nothing to do with the problem. After reading the possible culprits I checked the dimmer switch. It was completely maxed out to the right. Turning it down fixed the problem. Thank you.
