Interior light´s not working

[schraxx]

Hi All,

i own 2008 Ram QC 5.7L and currently do have a electrical problem with my interior lights.
I´m living in Germany and as you may can imagine, this type of car is not very common here - therefore it´s difficult find somebody with experience on that.

That´s why i was hoping you guys may have an advice on how/where to start the search for the issue.

The problem is the following.
My Interior lights (Map and Dome light) won´t turn on when any of the doors will be opened, nor wen i press the unlock on the keyfob (acc. to the owners manual they should do), nor when i dial the dimmer to the top position. However, i still can turn on the map lights manually by pressing.

It seems to me very unlikely that all four ajar switches and the dial wheel are broken, but more likely that there is some problem at the control module (TIPM??) or on the wiring from the module to the lights.

Does anyone have an idea how to find or at least further narrow down the problem?

BTW: The fuses are OK, this was the first thing i´ve checked.

Thank you in advance

 

[Fast69Mopar]

Hi All,

i own 2008 Ram QC 5.7L and currently do have a electrical problem with my interior lights.
I´m living in Germany and as you may can imagine, this type of car is not very common here - therefore it´s difficult find somebody with experience on that.

That´s why i was hoping you guys may have an advice on how/where to start the search for the issue.

The problem is the following.
My Interior lights (Map and Dome light) won´t turn on when any of the doors will be opened, nor wen i press the unlock on the keyfob (acc. to the owners manual they should do), nor when i dial the dimmer to the top position. However, i still can turn on the map lights manually by pressing.

It seems to me very unlikely that all four ajar switches and the dial wheel are broken, but more likely that there is some problem at the control module (TIPM??) or on the wiring from the module to the lights.

Does anyone have an idea how to find or at least further narrow down the problem?

BTW: The fuses are OK, this was the first thing i´ve checked.

Thank you in advance

To the best of my knowledge, the courtesy lamps and reading lamps are controlled by the lamp driver in the instrument cluster. Basically, they are hardwired to the instrument cluster so when you open the doors, the door lock actuator sends a signal to the cluster to activate the lamp driver and therefore turning the lamps on.

The courtesy and reading lamps are wired into the C1 connector at the cluster. They all work off a common ground too.

We need to verify that the instrument cluster is receiving a signal for the door lock actuators. If we have a good signal from the door lock actuators then we need a scan tool to operate the inputs and outputs of the instrument cluster to see if it still has the ability to control the lamps.

 

[schraxx]

Thank you for your feedback.

I guess a standard affordable obd scanner won’t do the job right?

Do you have an idea if there is an accessible spot close to the cluster where I may can check I.e. with a digital multimeter if there is any output from the cluster ?

 

[Fast69Mopar]

Thank you for your feedback.

I guess a standard affordable obd scanner won’t do the job right?

Do you have an idea if there is an accessible spot close to the cluster where I may can check I.e. with a digital multimeter if there is any output from the cluster ?

A basic scan tool won't do it. You need one with some added abilities.

Now, for testing the instrument cluster output for the lamps. You can remove the cluster and pull it forward enough the turn the cluster sideways to gain access to the connector.

Take a look at the cluster wiring diagram and find the courtesy lamp driver and reading lamp driver outputs and backprobe with a paper clip and attach your test light or DVOM to the paper clip. Operate the door latches and dimmer switch to see if you are receiving the inputs to turn the lamps on and check the output from the cluster to see if the cluster is doing its job by commanding the lamps on.

 

[schraxx]

Some little Update:
Meanwhile i also found that
-rear left Door Lock isn´t working anymore (checked the cable in the door, the are ok but there is no power/signal on the door lock wire)
-front left door Lock is stops working occasionally

I also have checked for DTC´s and found those two
Cargo Lamp Control Circuit Open
Cabin compartment Node/cluster internal

I tend to believe that the cause is a faulty cluster, but seems the only way to proof this (before buying a new on) will be your proposed method.

 

[Chris Stevens]

I just had the same issue on my '08. check the connections on the back of the gauge cluster, make sure they are tight. If that don't work, you will most likely have to change the cluster like I did.
I bought a used one with the same part number for $100 on ebay. luckily, the mileage was almost exactly the same.