Chevy Express dome light issues...

[galladanb]

We have a 2008 Chevy Express 3500 extended, cargo version not passenger version.
I am looking into how the dome light system works.



With the dash switches, I can have the system over ridden, meaning no light.
I can also turn the dome light on using the push pull switch.

The side doors and rear doors work as expected, open door, light on.
Close the doors, the light goes out as expected.

So, all is well, so far...

But... The front doors do not turn the light on, and there does not appear to be a switch anywhere in the frame. I believe the only wires are for the speakers. I don't have power locks or windows.

Am I missing something?

Additionally, I want to put an led light in the overhead dome, both for brighter light, and less power consumption.

So, everything I find on the webs suggest that the bulb is this one.



I bought this one, and it won't work.
I also turned it around in case there was a polarity issue.
At first I thought the bulb was dead. So, I bought another one thinking it was, I used my multimeter to check for continuity. But no, so it must be dead.
And so was the second one. Doesn't work.

What am I doing wrong?

 

[tx2sturgis]

This is a guess: is there a menu setting in the dash or a switch on the lamp itself?

And another guess: the door switches may actually be in the hinge, or the 'stay', inside the door frame, or maybe in the latch. I've seen that before. 

And most of those multi-LED replacements can't be checked with a continuity tester, they have too many components in the circuit that regulate, divide, and send current to each LED module.

 

[galladanb]

HI Guy, before I considered a meter check, I tried the led bulb when the normal one WAS ON.
IN OTHER WORDS, I TURNED THE LIGHT ON, AND PULLED THE OLD ONE OUT, AND PUT IN THE LED.
NOTHING.
TURNED IT AROUND, AGAIN NOTHING. In case of polarity...

That's why I thought the first LED bulb was bad. I will try the second one tomorrow!
(Sorry, didn't realize the caps key was on, crap!)

Tx2, the switches and markings are just like the user manual shows, see my first image above.
And everything works just like it says it should.

It's just that the front doors don't turn the light on in any conditions...

That's what odd...

 

[Weight]

Check the door switches. PO may have disconnected them to prevent the overhead light coming on.

 

[galladanb]

Weight, I already posted that there are no visible switches.

Do you actually know what or where the switches are?
I can't see anything that is a switch?

 

[tx2sturgis]

If you want to check those LED bulbs you bought, just hook them up to a 12v battery using a pair of alligator clip leads.

 

[Weight]

Sorry i missed that. There are many posts found on google that show lots of people have problems with the light switch on your model. To much research for me. As for the bulb. as tx2 said, try a jumper at the battery,see if the bulb works. Check the socket for the voltage. computerized vehicles have lots of strange needs.

 

[travlinman and wife]

pull the light fixture out and see if wires are connected. po might have puled a wire so the front light does not come on when back door is open so the cab area would stay dark.

 

[galladanb]

Yea, the light fixture does work, but only with the side and back doors.
The front ones do not turn the light on...

So, I guess I need to find out what and where the front door switches are.
The door checks or stays are perhaps my best bet?
I think I will have to pull the door cover plastic and take a look...????

Such fun!

 

[tx2sturgis]

I found this part, a 'door jamb switch' listed on Rock Auto.

Maybe it's there, hidden under some weather stripping?

Dunno.


http://www.rockauto.com/en/moreinfo.php?pk=97820&cc=1442039&jsn=10660

 

[galladanb]

Interesting, but I didn't see anything like that part...

But thanks for checking!

I'm still searching...

 

[Stanvan]

I don't know for a fact, but it is my belief that the switch for the front doors is built in to the latch. On my '16, I get separate warnings for the back and side doors (ajar), but just the chime for the front. It seems to me that the signal from the doors should go through some sort of ECM or BCM, and then routed to the override switch. My experience with BCMs suggests there may be a fuse involved.

Heck of a first post.

 

[tx2sturgis]

Heck of a first post.

Hey, we all gotta start somewhere.

You might want to post a short intro in the newcomers section.

And welcome!

 

[gapper2]

Found this on a chevy forum:

" bigthing

Before any repairs are attempted, ensure that the dome over ride (push button) switch has not been activated. Vehicles may arrive from the assembly plant with the dome over ride activated due to battery conservation at the assembly plant(s). The dome over ride switch is located on left side of I/P and to the right of the headlamp **** (as shown below). If this switch is pushed inward, the dome over ride feature is activated. There is no LED to indicate the feature has been activated, the button will be recessed slightly from its normal position.

That's exactly it! My 2008 Express 3500 manual describes it but in a not-so-obvious way. The override button doesn't look like a button and I missed it the first time. Now that I pushed it, the dome light works! Thank you so much. "

hope it helps.

 

[tx2sturgis]

Wow...

Dome override switch....whooda thunk it. 

 

[galladanb]

Ok, again... The dome light works. It is not over ridden... It can be turned on and off with the knob... The dome light works with the side doors... The dome light works the back doors...

The dome override functions perfectly.

The front doors do not operate the dome light at all. That is the remaining problem...

 

[Stanvan]

Wow...

Dome override switch....whooda thunk it. 

A common thing on GMs.  Handy for sleeping babies, clandestine meetings...

 

[galladanb]

Stanvan, welcome to the forums!

Thank you for the thoughts! Curios? Why do you think the switch is in the latch? Is there a drawing that you could share or a link to one?

And... Are your separate door ajar indications sounds or dash lights?

Thx!

 

[galladanb]

Oh... Stanvan, did you mean the first post in this thread?

If so, thanks!
If not, which one exactly? Sometimes comments can and are taken several different ways?

 

[tx2sturgis]

A common thing on GMs.  Handy for sleeping babies, clandestine meetings...

Yep but on my Ford it's on the lamp itself....not 'hidden' in the other switches...

The last GM I owned was a 1994 Chevy pickup, and you were limited to pulling the dome light bulb out.