dome light door switch?

kbeefy · Post by **kbeefy** » Mon Oct 12, 2009 5:32 am

Anytime my dome light switch is moved from 'off' the light comes on. There doesn't seem to be an 'auto' function.

'92 T-leg sedan.

I assume the door switches are all good because the display on the dash works fine. When all doors are closed (and display shows them as being closed) if I put the dome light switch in the middle position it turns the light on.

Any tricks? A relay I should be looking for? a schematic would be helpful.

BSOD2600 · Post by **BSOD2600** » Mon Oct 12, 2009 10:07 am

All the FSM's are posted in the what you need to know forum...and sadly it's from a 92 FSM where there was only a on/off switch

kbeefy · Post by **kbeefy** » Mon Oct 12, 2009 4:17 pm

sweet, thanks!

pretty much what I had thought it would be, only way I can see for it to fail the way mine is would be a switch isue, I'll try to take it apart.

Post by **Legacy777** » Mon Oct 12, 2009 5:50 pm

In the middle position, it should go off when the doors are closed.

Does the little light near the fuse panel in the driver's foot well area go off when the door closes?

BSOD2600 · Post by **BSOD2600** » Mon Oct 12, 2009 6:13 pm

Legacy777 wrote:Does the little light near the fuse panel in the driver's foot well area go off when the door closes?

Wait, there is a light there? Now I'm going to have to check both my cars since neither have had illumination from that area...

SPUMONI_RT · Post by **SPUMONI_RT** » Mon Oct 12, 2009 7:55 pm

The light down there has a white rubber cover over the bulb to make it not as bright so it isn't that noticable.

Post by **Legacy777** » Mon Oct 12, 2009 8:06 pm

I think it's just a plastic cover. At least on my car, I believe it's just a plastic cover.

BSOD2600 · Post by **BSOD2600** » Tue Oct 13, 2009 1:16 am

Anyone have a picture of the area it's suppose to be in? Can't find it in my car or the parts manual.

kbeefy · Post by **kbeefy** » Tue Oct 13, 2009 1:49 am

no, in the middle position the dome light comes on just like in the 'On' position. Doors don't seem to have any effect.

i haven't noticed any lights in the foot area, I'll look later.

BSOD2600 · Post by **BSOD2600** » Mon Oct 19, 2009 11:46 pm

Figures, Karma. Took the headliner/sunroof out this weekend to fix the leak. After re-assembling everything guess what, my doom light auto switch no longer works! Damn thing stays on in both the On and Auto positions. Yes, it was working just fine before the headliner removal...

kbeefy: Ever figure out your issue?

SPUMONI_RT · Post by **SPUMONI_RT** » Tue Oct 20, 2009 3:40 am

BSOD2600 wrote:Anyone have a picture of the area it's suppose to be in? Can't find it in my car or the parts manual.

Look right above the fuse panel under the dash. You may need a light.

kbeefy · Post by **kbeefy** » Tue Oct 20, 2009 5:25 am

nope, haven't had a chance to mess with it yet.

I looked around my fuse box and couldn't find any light either.

BSOD2600 · Post by **BSOD2600** » Fri Nov 20, 2009 9:40 pm

Alright, this lack of a doom light is really starting to bug me.

Took the doom switch off and measured that the lines are always supplied with 12V, regardless of the doors open/close. That doesn't seem quite right, since when its in the auto position, it should have power via the combo meter, right?

Do sedans have the rear gate indicator on the combo meter? I know my TW did, but not having the SS for long, I'm not sure.

Anyone have an updated schematic for the doom light? The one I posted above is for a 2 position switch, and my car has 3 (off, auto, on).

Post by **Legacy777** » Sat Nov 21, 2009 12:50 am

The diagrams in here should be up-to-date

http://www.main.experiencetherave.com/s ... and_Elect/

I do not believe the sedans have the rear gate indicator. My 90 Legacy doesn't have it.

BSOD2600 · Post by **BSOD2600** » Sat Nov 21, 2009 1:20 am

Yea, thats the same 92 wiring diagram I have too via 1992_legacy.pdf. The 94's must not have had the 'step light', since there aren't any lights at the bottom / side of the doors as the diagrams show.

I don't think the diagram is correct since it shows a 2 pole switch, while mine is 3 (unless the diagram just assumes that the Off position doesn't need to be shown?)

Anywho, whats the next step to troubleshoot this issue? As the OP, all the door indicators on the instrument cluster work as expected -- all off when doors are closed, each one turns on when the correct door is open.

Post by **Legacy777** » Sat Nov 21, 2009 2:24 am

All the diagrams include the 90 MY are like that. I think they just don't show the "off" position.

There are some diodes in the diagrams in section 6-3 that you may need to check/test.

BSOD2600 · Post by **BSOD2600** » Sat Nov 21, 2009 2:40 am

Legacy777 wrote:There are some diodes in the diagrams in section 6-3 that you may need to check/test.

Yikes, that's not exactly an easy process. While my Craftsman multimeter tool does have a diode setting, I'm not sure if one can properly test it with the diodes still in the circuit. The diode testing setting applies a low voltage through the diode -- and if its still connected to the rest of the circuit, it cannot get an accurate reading. Furthermore, I'd also have to find the location of the diodes, presumably somewhere in/on the cluster circuit board. Diode testing info

This issue started after taking down the sunroof assembly and repairing it. So I'd be more inclined to think its a wiring issue with something outside of the cluster. Obviously the wire to the roof light works and has power. The sunroof works too, so all the wires associated with that stuff is properly connected. I forget what other wires/connectors were up there that I might have missed that would also be part of the light circuit.

kbeefy · Post by **kbeefy** » Sat Nov 21, 2009 4:46 am

I still haven't checked mine any further, but I have the same symptoms you describe. Now that it's getting darker around here, I'd really like an automatic dome light.

I was assuming our '92s had the same wiring schematic as shown above, and the off position just wasn't illustrated.

kbeefy · Post by **kbeefy** » Sat Nov 21, 2009 4:58 am

looking at the diagram, I think all the diodes do is prevent the dash from lighting up when you put the dome in automatic mode. I don't believe a failed diode would cause the failure we're having. If it failed open then that door wouldn't trigger the dome, if it shorted your dash would weird out. Theres no way you killed all the diodes messing with the headlinner.

kbeefy · Post by **kbeefy** » Sat Nov 21, 2009 5:08 am

If I've read the schematic correctly, at the roof switch there should be a wire that's hot all the time, a connection to ground, and a switched ground wire (or wires) that switches to ground with the doors opening.

tahiti350 · Post by **tahiti350** » Sat Nov 21, 2009 6:32 am

just a thought (one of my own, so it may be WAY off track) Doesn't the door open light on the dash read from the door latch, not the interior light contact switches? If so you "could" have a bad jamb switch that's not breaking contact...

i may have to go out and check this theory now... damn it, it's raining again...

BSOD2600 · Post by **BSOD2600** » Sat Nov 21, 2009 7:07 am

tahiti350 wrote:Doesn't the door open light on the dash read from the door latch, not the interior light contact switches? If so you "could" have a bad jamb switch that's not breaking contact...

My reading of the circuit is that the combo meter is only illuminated once a door switch is closed.

It would be awesome if someone could post Section 5 (body) of the FSM.

tahiti350 · Post by **tahiti350** » Sat Nov 21, 2009 6:03 pm

Okay, just went out and checked on my '90 wagon and the door open light AND the dome light do both work off the plunger switch.

So, if your door open on the dash is working right then could it be as simple as a bad dome light assy??

BSOD2600 · Post by **BSOD2600** » Sat Nov 21, 2009 9:12 pm

I suppose the dome switch could be bad... tried taking it apart, but really not much to it. Just a simple 3 position switch. Should be easy enough to test the functionality with a continuity tester though.

BSOD2600 · Post by **BSOD2600** » Sun Feb 21, 2010 11:08 pm

Well I fixed my dome light issue today, but not really sure how. I knew the wire in the "auto" position must be getting grounded somehow. Tested it with the multimeter and it confirmed my suspicions.

Anyways, I removed all the plastic trim and pulled the headliner part way down. Re-attached the dome light (must be screwed in!) and then the damn thing worked as it should. I looked over the wires feeding the light back to the dash and it all looked fine with nothing pinched. Carefully reassembled the headliner, etc testing as I went.

I guess time will tell when I drive around town for a bit if something gets jiggled and shorts out again.

legacycentral bbs

A forum for 89-94 BC-BF(BJ) Legacy Owners and Fans

dome light door switch?

dome light door switch?