e34 dome light-what do you think?

[KenC]

Are you going to do a little write up along with the pics?

Thanks,
Ken

[gearheadE30]

Okay, here goes nothing. Unfortunately I don't have pictures or measurements for everything, but if any of you decide to go for it, it's pretty straightforward.

Things you need
-Check panel
-e34 dome light
-soldering iron
-wire
-plastic bonder
-dremel with cutoff wheel
-some form of sandpaper/sanding drums/files etc.
-patience :)

though the whole thing, remember that it is always easier to take material off than it is to add it back. I kept the entire assembly a few millimeters too long with every cut I made just to be safe.

First, take a check panel and cut the back off. It doesn't have to be pretty, because you won't be using the back again; just the sides. You can try the 318 blank panel, which deoesn't have to be cut, but I think the lip on the short edges is too short to hold the light in place.

Anyway, here's a pic of the panel with the back off:


The innards of the panel pull out. There are small nubs on the inside of the housing that hold everything in; with a hard enough push, everything pops right out. It may help to pull outwards on the long sides of the panel just to create a little more clearance.

Here's a pic of the innards removed:


All of the parts are stacked on top of each other:


Next, take the e34 light and pop the plastic lens off of the opaque housing. It just snaps on. Be careful not to break the tabs, because you will need those to reassemble everything. Unfortunately, I don't have pics of this.

The lense needs to be cut down to length first. You will use this as a template of sorts to figure out where to cut the frame later.

This is where the entire project becake a bit of a trial and error project. The length that I cut out was roughly 4.5 cm long. I'd start with cutting out 4ish cm and going from there to make sure it all fits. It should be pressed snugly between the two ends of the check panel housing. Do not cut between the two switch holes, because that will make it downright impossible to modify the frame. I suggest using a dremel and cutting along one of the black sections of plastic like this:


The center part can be discarded, so you end up with this:


When you get the correct length, it will essentially hold itself into the housing with friction. The nubs on the inside of the housing keep it from falling out of the bottom. Final product of this step will look like this:



In my car it didn't matter which way the housing snapped into the check panel hole. I'd assume this works for all e30s, but the 318 may be different with its incomplete panel. If it does matter, just be sure to pay attention to the orientation of the map lights when you are modifying the lense, as they are directional.

The next post will show the harder part-getting the frame to work. It might take alittle while for me to post this because I have to go run some errands. Real life calls...

[TDE30]

Great write-up and good idea for one of the most poorly-lit cars I have ever come across.

[BrewCity11]

Great write-up and good idea for one of the most poorly-lit cars I have ever come across.

+1. Thanks

[gearheadE30]

Okay, here goes part 2. Sorry for the lack of pictures. If my explanations are inadequate or you just want more pics, I may be able to take some more of the finished product just for better perspective.

Okay, now that the lense modifications are done, pull the lense back out of the check panel housing and snap them back into the e34 dome light frame. Use a sharpie or a knife to mark where to cut, pop the lense back off, and cut the frame. The part cut out will be roughly between the two lines in this picture:


At this point, DO NOT cut through the metal traces in the light. Also, there are wires that run through a channel in the plastic; be sure to pull those out before cutting. Make sure you keep the plastic bits, as you will use them to strengthen the frame of the finished product.

There is a red wire hooked up to the trace that runs the length of the light; you will need to unsolder it and resolder it on closer to the double-switched side of the light. Be sure to use some sandpaper to scuff the surface of the metal to ensure a good bond.

Now, the two ends of the frame will be connected only by this trace. There may be an easier way to do this, but this is what I did. Look at this picture to get a rough idea of what the trace looks like:


The side closest to the single switch does not need to be cut. The trace bends out in the middle to create the light holder; about 1cm after it returns to its straight path, cut it with the dremel. Now that the sides are separate except for the wires, you can press the two ends of the frame together. This is going to be roughly the finished product length. Now is a very good time to check the lense fitment and make sure that the frame cuts line up with the lense cuts. This is harder to fix if you don't do it now.

The end of the trace that was cut, with the two halves pressed together, will be resting farther down the length of the trace now. Use the soldering iron to reconnect the trace. This takes a fairly strong iron, and try not to melt the plastic too much as it will warp.

This step is somewhat optional, but I found that it makes the edges of the light sit a lot flatter with the check panel housing. Put the lense on the frame and set a piece of fairly heavy-grit sandpaper on a flat table or the floor. Sand down the short end of the light maybe a millimeter or so just to flatten it out. The factory design isn't quite straight.

At this point, with the trace resoldered and the lense/frame alignment checked, I put the lenses back on and stuck the entire assemply into the housing to make sure that it fit firmly in place. It should be fairly difficult to get in there, but it won't take much force if you get it right.

Once the fit is fine-tuned to where you want it, get out those plastic segments of the frame that you cut. As shown in this picture, the face of the frame and lense sticks out beyond the actual frame:


In this space, use the plastic bonder to glue the rail parts in parallel with the actual frame. This is somewhat hard to explain, and unfortunately I don't have a picture right now, but the idea is to attach the rail part sitting flush along the actual frame to provide more surface area for the bonder. Be sure to scuff the surface of the plastic to ensure a good, strong bond. The bonder may take awhile to cure; make sure you check the lablel.

With this done, look at the holders for the lights. The map lights are essentially the same as original. The middle, unfortuately, doesn't work this way. There is no way to reuse the little metal reflector that was behind the light because it is simply too long. The stock e34 bulb is quite thick, so I used an e30 dome light bulb in its place

In order to get it to fit, I had to mount it diagonally. In this picture, you can see one of the bases of the bulb, just to get an idea:


To do this, the existing prongs have to be bent back to the black lines on this picture:


Try to bend them in a way that keeps the bulb from toughing the plastic, as it might melt. I have had no problems with mine the whole time I've had it in, however.

After doing this, replace the lenses if you have not already done so and fit the assembly into the check panel housing. There is no need to glue it in. It should be held in with friction from the sides of the housing and by the nubs in the housing. There is quite a bit of room to get it to sit however you'd like.

For wiring, because there is no power to tap by the mirror in my car, I ran a wire above the headliner from the driver's side dome light. This is a lot easier than it sounds. Pull off the weatherstripping around the door frame and you will be able to pull down the side of the headliner and the plastic sunroof panel piece. This may be easier if you remove the sun visors. The wire I had was stiff enough that I could shove it under the plastic piece and have it pop out the other side straight forward of the original dome light at the windshield. From there I just tucked it in above the trim panel until I reached the check panel hole.

You will need 3 wires; one for power, one for door power, and one for ground. the e34 light has 4 leads for whatever reason; you only need 3. Unfortunately, I forget what they are. I can check if someone reminds me in a few days :).

I used the e34 body-side plug soldered to the wires I installed just so that I didn't have to come up with my own plug arrangement. It fits fine in the remaining space.

When you finally pop the light in, make sure the maplights are lined up pointing down. If you don't it isn't a big deal because the light pops out just like the check panel.

the e34 switches have 3 positions- off, on, and door switched. For some reason this confuses some people, so I figured I'd point it out.

I probably forgot some of the build, so if there is anything that seems to be missing or doesn't make sense, post here or shoot me a PM and I'll help you out. If you want specific pics or instructions for anything else, I can also do that. Hope this helps you all out, and have fun :)

Jordan

[ZM Blue Devil]

you are the man, Ive got two of these dome lights sitting around, will do it this weekend. Thanks again.
L

[dude8383]

excellent write up!

now all i have to do is put aside some free time and install this as well.

i can take progress pics while i build my e34/e30 maplight :)

[Motorsports]

Am just wondering if the check light is going to stay on all the time.

[gearheadE30]

Thanks guys :)

Motorsports: I wish I could help you out, but the 318is doesn't have any of the check panel wiring so I don't have a light there anyway.

[matixmattix]

Which 3 wires out of the 4 from the e34 light did you use exactly? I'm a bit colorblind but from the looks of the e34 dome/map light I'm trying to wire up it has: one grey/red, two browns, and one green/red. On my e30 drivers side dome light it has: one grey/red, one brown, and one green/red. I just need to know which 3 e34 wires are you using, and for those that are being used, which of the e30 wires are you connecting them to exactly? It's driving me nuts, please help!