Map Lights on with Dome light Mod

Big thanks for this mod.. What a difference..! Had become a habit of manually switching on the maps lights everytime I stop, now all auto..!!

 

Will stress that you must disconnect the battery doing this mod.. Even tho I had, I tried very carefully to keep the two wires on the plug (which you have to swap around) from touching each other, veeery difficult and seems this is what blows the BUI..

Managed to do all of this without solder, used small block connectors and on the dome light, I wedged the wire under one of the metal strips connected to the middle (brown) wire, similar to how folks have been connecting the wires at the map light end..

Quite daft that this is not done at Subaru... Heated seats next..!!

 

Yamon, is it possible you have some condensation in your dome light? My leggy is the worst car I have ever had for condensation and is a running battle to wipe off all the interior water on the windows every time I get in it in the winter.. just a thought..

 

Did you change your cabin air filter? Unless you are running recirculation a lot Legacy gets a good air flow, taking the filter is clean.

Hi..

Filters and fluids are next on my list of 'to do'.. Since getting the car in June, I have been trying to get all possible maintenence done, filters are next and I will certainly do the cabin pollen filter.. Does it really make such a difference to condensation..? Cant quite picture how but it will be done anyways.. Will let you know if any difference..

Turns out my condensation is due to a leak in the passenger footwell (not aircon).. Going on a ramp Tuesday for an inspection..

There is a reason the map lights do not light up with stock set up.

 

The trace carrying current from the pin to the FET measures 1mm wide. The calculator here shows that a 1mm trace can support well more than 2.5 amps (about 16 actually). So it looks like the FET's 30W rating is the limiting factor. The existing 12V8WAL bulbs are unknown wattage, though. Presumably 8W? With 2 on the original circuit, each would have to be 15W or less to not exceed the FET's power rating. But if they are indeed 8W, then the maps lights added would give a total of 32W, slightly exceeding the stock FET's rating.

 

(not my work, full work up click link)

http://www.subaruforester.org/vbulletin/f85/body-inegrated-unit-dome-dimming-circuit-data-repair-83167/

4+ years after this mod, still running incandescent bulbs, no issues. Good to know how to repair and/or beef up the BIU though.

11.2+ years here. Still works.

Yeah, anyone who cares enough to do this mod certainly cares enough to switch to LED bulbs, IMHO. I have to admit though, when I bought my LED bulbs, it never occurred to me how they might behave with the BIU dimming circuit. But mine has been going about 8 years with no problems. LEDs came from autolumination-dot-com (see post #188 for details). Edited March 2, 2017 by RustyShackleford

Will stress that you must disconnect the battery doing this mod.. Even tho I had, I tried very carefully to keep the two wires on the plug (which you have to swap around) from touching each other, veeery difficult and seems this is what blows the BUI..

Hard to believe the wires touching would blow the BIU if the battery is disconnected. Unless somehow there's still some residual voltages on capacitors or something. Maybe disconnect the battery and wait a half-hour, to be sure ? I think that was the rec when I temporarily disconnected my passenger-side airbag, waiting for the dealer to get the repair part.

Purchased an 06 LGT a few weeks ago. Dome light, map light, and trunk lights all do not work. I pulled the dome light and map light covers and saw that this mod was done (dome to map) and after reading all of the replies on this thread i havent found anyone with similar results as mine but figured it would be worth asking here. WIth all the talk of fried biu...is it possible that the problem may be with my biu? Everything works except map dome and trunk. I have power and continuity where i should and havent found any blown fuses (checked the ones mentioned in this thread). Also worth mentioning the wiring modifications all look clean and mirror the O.P instructions

Purchased an 06 LGT a few weeks ago. Dome light, map light, and trunk lights all do not work. I pulled the dome light and map light covers and saw that this mod was done (dome to map) and after reading all of the replies on this thread i havent found anyone with similar results as mine but figured it would be worth asking here. WIth all the talk of fried biu...is it possible that the problem may be with my biu? Everything works except map dome and trunk. I have power and continuity where i should and havent found any blown fuses (checked the ones mentioned in this thread). Also worth mentioning the wiring modifications all look clean and mirror the O.P instructions

No longer super familiar with the circuit, but recall the map and dome lights all get 12v at one terminal and are activated by pulling the other side to ground (0v). I'm thinking if you use the switch on the map lights, and they don't come one, something else is wrong, because that switch should pull the other side of the map lights to GND without requiring the BIU to be working; except it sounds like you checked and saw 12v coming to the map light assembly. Similarly, if the dome light does not work, even in the switch position that turns it on directly (without the door being open), then something besides the BIU is the culprit, because that switch should pull the other side directly to GND.

 

I'm not sure where the trunk lights fit into all this: don't have time now to find that part of the wiring diagram in vacation pix.

 

I'm thinking the previous owner tried the mod and screwed it up and who know WTF is wrong. So basically, you need to look at the wiring diagram (see post #178 on page #12 earlier in this thread) and use logic to troubleshoot from there. Maybe not too helpful - sorry.

Edited March 19, 2017 by RustyShackleford

Purchased an 06 LGT a few weeks ago. Dome light, map light, and trunk lights all do not work. I pulled the dome light and map light covers and saw that this mod was done (dome to map) and after reading all of the replies on this thread i havent found anyone with similar results as mine but figured it would be worth asking here. WIth all the talk of fried biu...is it possible that the problem may be with my biu? Everything works except map dome and trunk. I have power and continuity where i should and havent found any blown fuses (checked the ones mentioned in this thread). Also worth mentioning the wiring modifications all look clean and mirror the O.P instructions

 

If you want to check the IBU it's not difficult to test for bad transistors and not hard to pull. I can provide instructions later when I get home.

Edited March 21, 2017 by scoobydrvr

i got the dome light and maps to come on. It was a combination of a fried BIU and the previous owners hack ass wiring jobs to kind of cover it all up. He did the map/dome light mod and guessing screwed up the biu. i dont really understand how this helped or would have prevented the dome and map lights from working but i replaced the bulb in the trunk and then wiggled the bulbs on the dome and map and they came on. Then was greeted by a dome that doesnt dim off. Before all of this i definately played with the bulbs in the dome and map...kind of confused how it all worked but theres a mess of splices and t connectors in the trunk wiring so who knows...but i got a dome light even though its only operable by switching the light on itself but it will work for now.

 

If you want to check the IBU it's not difficult to test for bag transistors and not hard to pull. I can provide instructions later when I get home.

This would be much appreciated! ill pm you

Here is my walk-through for BUI repair, it covers both FETs for dom lights and stereo illumination:

 

http://legacygt.com/forums/showthread.php/diy-05-bl-bp-stereo-heat-switches-mirror-switch-illumination-177954.html

11.2+ years here. Still works.

 

Hey, is there any chance you could repost the pics from the OP, using another service? I realize Photobucket screwed a lot of people over, but even posting them here at this end of the thread would be a useful reference for people who are interested in doing this mod (like me). I could probably figure it out but it's nice to have the pics.

Hey, is there any chance you could repost the pics from the OP, using another service? I realize Photobucket screwed a lot of people over, but even posting them here at this end of the thread would be a useful reference for people who are interested in doing this mod (like me). I could probably figure it out but it's nice to have the pics.

 

If you use Chrome try this, I can see the pics in the first post with it installed.

https://chrome.google.com/webstore/d...fegnfnflicjjgj

Wait, can someone explain to me why we can't see the pix anymore ? (At least I can't, using Chrome on OSX).

Photobucket requiring OP to upgrade his account?

from within Chrome, google search "photobucket embed fix"

Install the extention

Restart Chrome

 

All images appear as before

I will be doing this mod shortly, now that I have full internal LED's

 

Does anyone know if the wiring is and different for the PostFacelift (07-09) Legacy's?

Wait, can someone explain to me why we can't see the pix anymore ? (At least I can't, using Chrome on OSX).

 

Photobucket eliminated free accounts and they've "blocked" image-hosting everywhere for everyone who hasn't paid their ridiculously high annual fee. Obviously the block is reversible (for now), which is great.

 

There's a Firefox extension for this also, with the same name.

I did this mod a couple of years ago and the map lights come on with the door open and then fade out with the dome light as they should.

 

HOWEVER, I've never been able to get the map lights on by themselves. I've been over the schematic, looked at the pics, and double checked (probably more now) the wiring and I still cannot get the map lights to come on. I even removed the diode on one side to see if that worked. Nada.

 

Has anyone else had this problem and got it straightened out? I'd like to once and for all.

 

Thanks for any help. It's a simple circuit but it has me stumped.

I need to do this mod but the pictures are not showing clear can you help?

@bobnorris not my video but there is a video here:

https://www.youtube.com/watch?v=uCEW-1iwups

Edited January 19 by xekon

I did this a long time ago and it worked great for a few years.  Then the lights wouldn't come on at all when opening the door.  I can turn them on manually, so they work.  Any ideas why they stopped working when the doors open?