Suggestions on Cluster Lighting (there appears to be a dark spot)

[muddycharles]

Hi Everyone,

As I work through the car to clean things up, I have a question for everyone. The cluster lights appear to be ok (in the sense I can see the whole cluster - but there is a dark spot between the RPM and Speed that does not seem to be bulb related.

I saw this ..... - has anyone else tried this (seems like a lot of work)

https://www.mforum.net/forum/e36-m3-...-dark-spot-fix

Im struggling to understand how glue can cause a dark spot? I would have guessed bulb, but from studying the link it appears there is no bulb there.

Half of me says leave it, but the OCD side is going to complain

Also - since I am going to change the steering wheel - taking the cluster out will not be a big deal. Do the lightbulbs of the cluster degrade over time anyway? Should I proactively change them?

Any suggestions are appreciated.

[Braymond141]

I just got your email. Will respond to that next.

It's not exactly glue, it's an always tacky adhesive. Years of the gauge face expansion and contraction cause bubbles to form where the gauge face no longer lays flat adhering to the glue. That is what causes the dark spots. You also cannot just fix it by pressing the gauge face back down, they come back.

The reason the glue layer is so important is due to the light optic design of the gauge face frame. Frosting the light frame like I show in my guide eliminates the need for the glue as the light is diffused across the surface. You can also relgue the face down with a removable photo tack spray (like Pixie Spray).

The bulbs burn spots into the glass but in the countless clusters I have done, I've never seen an improvement in clarity from just swapping bulbs. Doesn't hurt to change them though.

[zellamay]

I've got one of those dark spots. Never knew why. I'm with that first half of you that says "leave it". It seems like such a minor blemish, and a lot of work to fix.

[Braymond141]

I definitely disagree. The juice is worth the squeeze.

[muddycharles]

ahahaha - thats the OCD side speaking. Im working the courage up to do this..... My main fear is the setting of the needles when you take them off. If they are not marked correctly it will get ugly.......

[MParallel]

Now I have never work on the inside of a cluster (well apart for some chromeline ring inserts when that was cool), but never where I had to pull the needles.

So this is all theory, but I jyst can't imagine there is only one perfect spot for the needle to be put back. I would like to see the (automated?) process when these clusters are assembled. There should be a range where the needle can rest againt the peck and still can do a full sweep when a currect is applied. Does the motor even know its 'zero' position?


I need to find that YT vid I watched recently about some custom display install and the guy had a neat trick for needle placement.

[Braymond141]

There is only one correct spot for their placement. This applies to most all clusters. The motors have physical stops left and right. The speedo, for example, at it’s full left stop is nearly where it needs to be for the correct position. With such little room for error, you can’t software you’re way out of that.

No such thing as auto calibration as some have incorrectly stated. There is no zero positioning.

[MParallel]

FWIW, I recall the procedure. The guy simply rotated the needles all the way to the full right (clockwise) untill it stops. Marked that position down. Then when reinstalling the needles at 'any' position and the rotated again to as far clockwise as where it was marked before. When you hit a stop before the mark, just keep pushing the needle till you reach the mark. Then it's back in its original position.

[muddycharles]

Question to Brian - how do you glue the cleaned display back on the clear plastic. Not clear from the link.

[Braymond141]

FWIW, I recall the procedure. The guy simply rotated the needles all the way to the full right (clockwise) untill it stops. Marked that position down. Then when reinstalling the needles at 'any' position and the rotated again to as far clockwise as where it was marked before. When you hit a stop before the mark, just keep pushing the needle till you reach the mark. Then it's back in its original position.

Definitely not how it works.