Dome light woes

Got near the ranch this afternoon and I notice that all the dome/courtesy lights are on and nothing will shut them off.

I tried the overide switch to no avail as well as all the other switches that control them, still on.

Finally yanked the fuse out, Pooof off :)

Off to get the chassis electrical manual out of the closet.

The circuit sends + to all the lights and then grounds the lights through either of the four door switches, the dash dimmer switch and the barn door switch in the back.

All the lines feed back through the main overide in the LH dash (94 Burb)

Checked out as much as I could without ripping the rig apart. Would seem that the circuit has found a shorter path to ground somewhere.

I am suspect that it may be in one of the overhead light fixtures. The spot reading lamps are hot all the time so all that would be needed would be a ground.

Oh well, just another anoyance to trace out.

Lovely having the big electrical diagram book from GM though.

Lays all the wiring out and shows where the wires go and where the connectors are located.

Gonna have to rip stuff apart and start checking to see where the short to ground is.

I do hope its not in some place that can't be reached by a human being.:eek:

At least its not something that is mission critical.

DaHoooley has not had dome lights since I bought it. I know what its issue is though. Custom overhead console that was wired wrong.

Idiots wired it in a series from one bulb to the next and so on and then to ground.

They glow very dim and if you take one light out they all quit. :eek:


Missy

OK it's off to the rodeo.

Sta down olast eavening and again this morning and studied the Wiring diagrams for the courtesy lights and got it all straight in my little head as to how the thing is wired.

The door switches all source their ground back through the overide switch on the dash (If equiped and most well endowed burbs have it)

The floor lights under the dash are on a separate feed from the panel.

Orange wire is hot and white is the ground side.

The standard models do not have the shutoff switch.

The dash dimmer switch when rolled all the way up connects the ground side buss on the panel directly to ground and turns on the lights.

Other than that the lights are dependant on a door switch.

Mine would stay on no matter what. With the overide switch completely unplugged the lights were still on. This effectively removes all the switches from the system and eliminates any issues there.

Now this morning I unplugged the line that feeds the overhead lights (both front and back.
Plugged the fuse in and Poof. the under dash lights work like they are supposed to.

The issue is somewhere in the overhead circuit. Specifically on the ground side

Likely the little tiny wires that feed this stuff have rubbed on something sharp overtime and made a good ground. This would bypass all the switches and the overide.

So now I know that its up top, I can rip the fixtures out and the console and see whats up.

At this point it has to be a chaffed wire somewhere.

Hopefully I can find it without having to rip the truck all apart. :eek:

The good thing is that the wiring is protected fairly well in the runs through the chassis.

The book shows all the connectors and splices ect
Here is a pix of the GM factory wiring diagrame books.

Bought these off Ebay, fairly cheap.

They are a Godsend in fixing electrical problems

Missy

Here is a pix of the wiring diagram that deals with the dome lamps and a few other items.

Easy to read and trace out the circuits.

This is not a schematic but rather a real time diagram that shows the different connectors, their location in the truck and many other important things.

Missy

I have an 85 and other than the under dash lighting it should be similar to the wiring you have in yours. Check the fixtures for damage first. My factory rear fixture had melted through the plastic housing and was grounded out on the brace that supported it. One other problem I had was wires which had burnt up. One of your best friends tracing direct shorts in a Vehicle like this is a continuity tester. and a DC Digitial multi meter. Once I fixed the direct short at the fixture I still kept popping fuses. Started checking continuity and found that I still had continuity between power and ground at the rear fixture. Evidently the previous owner decided to just keep putting bigger fuses in other than fixing or tracing the short and it burnt up a good chunk of the wire close to the back fixture. After looking at the cheesy aftermarket replacement piece for the lampholder and not being happy with the light output I bought an aftermarket dome light to put in its place. Same wattage but much better lense and reflector and much better light. It is square to the factory round style but it covered the hold nicely and looks stock.

Good luck on the tracing, hopefully its something simple.

Quote:

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Originally Posted by Robyn

Here is a pix of the wiring diagram that deals with the dome lamps and a few other items.

Easy to read and trace out the circuits.

This is not a schematic but rather a real time diagram that shows the different connectors, their location in the truck and many other important things.

Missy

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OK, I'm resurrecting this thread b/c I have the same problem Missy had: dome (courtesy) lights stay on no matter what. Kind of wondered what the outcome of Missy's problem turned out to be, but didn't see a followup.

I've ruled out the headlight switch, dome light fixtures, door jamb switches , etc. I have the full GM Factory Service Manual with the complete wiring diagrams. Pls see my signature below for vehicle specifics.

I have a short to ground on the white wire (circuit #156, it completes the circuit for the dome/courtesy lights) between the front and rear of the vehicle. The obstacle to finding where circuit #156 is shorted to ground is that I don't know where "Splice S246" is located. Splice 246 is where all the white wires are marshalled for the dome lights & door panel courtesy lights. Once I find it's location, I can separate all the white wires leading to the dome lights and door panel courtesy lights and track down the short.

The GM manual lists the location as "S246 (Utility/Pickup/Extended Cab) - cross body Harness, 6 cm right of rear body breakout". Two things bother me here: 1) there is no explicit location for a Suburban and 2) I have no idea where this "...breakout" is located.

Help! These short winter days mean I'm in my vehicle more in the dark, I really need the interior lights. Anyone have any info for me?

thx,

GS

Installing recon big rig ice running lights and trying to figure out how to make the courtesy lights come on when I open the door. Used test light to see if fuse went hot when door opens and switch button came out. No luck, courtesy fuse is always hot. Anybody else have an idea?

The dome light is a ground circuit.

The hot lead runs to the lights and the ground wire runs back and to the door jam switches

You should be able to run a hot line to your extra lights and run the grounds to the door jam switches.

You will need to run a ground to each door to get things to work whichever door is opened.

JUST A RECAP
The wires in the door jams are grounds only.

Good luck

I know a lot of us struggle with this grounded interior light wiring issue so I decided to revive an older post because of the great technical data in the previous posts and we all like to read this stuff. :)

So about a week ago the courtesy fuse snapped and I cringed. (yeah..the electrical challenges of an old 6.5 are like an old "Quaint" home they both equal work)
Having been through this all before and knowing my drivers side plastic door pin was suspect, I bought a new one, swapped it and....the fuse still snapped immediately upon insertion. Dang...a grounded hot wire somewhere.

I have an aftermarket radio and since lights and radio share the 20amp CTSY fuse I check the wiring there first. Nothing.

Next I pull all the interior lamps and inspect...nothing. Still blowing fuses.

Pull the drivers kick panel and door entry trim, nothing pinched in the main harness. Humm...need coffee...aahhh the brain starts to engage..and I get an idea "remove the feeds (Green connectors) at the convenience center to isolate the problem then disassemble the truck"

After a few minutes of trial and error I find the lead that supplies +12 to the illuminated visors to be the culprit. (Note to self: caffeine BEFORE troubleshooting) :rolleyes:

Turns out the passenger visor has an internal short. I will leave this visor disconnected since it has not been used in a long time.

I put the fuse in and whalah..dome lights and radio again. Whoot!...no wait...
My drivers door is open and the dome lights are off. This is not right.

After testing every door (and the dash switches) I find that only the drivers door fails to ground the interior lights.

The perplexing thing here is that the drivers switch is new and operates properly with the key buzzer. e.g. if the key is in the tumbler and the door is opened the buzzer is heard. I traced the pigtail from the drivers door pin until it combines with the main harness. Unfortunately it does not route directly to the convenience center.

Well...this one requires my GM wiring diagram supplement since all the pins are wired together and then route to the dome light override. It will show me where to look next....Now where did I put that 3 years ago when I was chasing grounds?

Long story short..I cant find it and I really want to get this sorted out. Partially because I want to come to end of job and mostly because my alarm wont trigger on the drivers door being opened. I race Mtn. bikes and I keep a very expensive bike in the back so need the alarm.

Does anyone have a wiring diagram that shows where the drivers door pin connects with the other door pins and the key buzzer?

Has anyone solved the same issue before? (searched but found nothing exact)

Thanks in advance,

-Eric

On my Burb's it would take between 30 seconds and a minute to turn off the dome light with the override if it was already on. My 97 had a bad driver's door switch, the 99 had a bad passenger's door switch. Once the override was pressed and left that way for a bit, no more dome light. Curious way to wire it....but apparently there's a delay relay or something in that schematic. Never dug into it much.