ZGERMAN

Hi guys,

I'm having big issues trying to identify the polarity of the 3528 Power Top LEDs, which are needed for the M5-look cluster mod.
I tried multiple different LEDs (I ordered both white 2000mcd and 2500mcd, with 1800mcd amber on the way...), but I simply can't get a read.

Just in case you're wondering, I'm pretty sure I ordered the correct LED types (as I followed PinguHK's awesome DIY to the letter..), but I just can't get the needle of my multi-meter to move; no matter what settings I choose. The meter has a fresh battery, and when I tested it - by holding the leads to another 1.5V battery, I got proper needle movement...

Well, it might very well be that my multi-meter is a total POS, but it was working fine when testing it on the battery earlier.


Can it be that it's simply not "sensitive" enough for the tiny LEDs?

BTW, what would be the correct setting anyway? DC? AC? 0.5? 500? [...as you can tell, I have no clue about physics, but that hasn't hurt me yet.. he he]. I have been trying virtually every possible setting, and also made sure to switch (+) and (-) leads [on the LED] every time, too.


It's a mystery to me....
Please help if YOU have a clue. - Thanks!


Cheers,
Armin

ZGERMAN

Just an idea... would the cluster (and the new LEDs) have to be under power so I can figure out their polarity... both the ones currently being soldered on, and also the new, loose LEDs?

How do I do that...??
It's been so much fun... until now. Dang!

ZGERMAN

Looks like I am just entertaining myself in this thread... he he!

Just made some progress... and I'd like to share it with you, just in case anyone of you runs into the same issue:

SOLUTION: I had to switch the multi-meter setting to "OHM" (x1k) - and all of a sudden I can see the needle move when touching the (+) or (-) ends of the LED.

However, how do I know which side is which?
Does is mean that it's the opposite of whatever makes the needles move... meaning, if I touch one connector of the LED with the black (-) lead and the needle does not move, that it's also the negative contact (because no electricity is flowing,,)??

I THINK I JUST ANSWERED MY OWN [%$E^#^^#!!] QUESTION...


He he... this is fun! I guess I'll get it done now after all...

Thanks, guys!!


P.S.: Let me know, please, if my logic doesn't quite check out after all...

rctmthouse

Not very familiar with this subject myself but I would assume the red is positive and black is negative so when you made contact and the the needle moved, then that's where the positive and negative will be when you solder it in. Please keep the thread updated if possible because this will be my next mod after finishing the maintenance issue on my car.

ZGERMAN

Well.. I got something accomplished this weekend... after 4 near-death experiences and 2 heart attacks...

First, the good news:
1.) I didn't f*ck up my cluster in the process (.. yay!)
2.) Even after some really lousy soldering work by yours truly (to change the tiny LEDs), the cluster is still illuminated - no blackout (..yay!)
3.) All needles are spinning as they should (...yay!)
4.) Since I wanted to play it safe, I only switched out the LEDs in the RPM gauge... [smart move!]
5.) I stayed away from spray-painting anything (yet), since I wanted to see if the LED replacements would work at all first.

Now... for the less good news:
The reason I am sharing the following "negative experiences" and mistakes with you is not because I am slightly retarded and find it "cool" to show the world what a dumb ass I am. On the contrary. I am hoping that a.) you may avoid my mistakes, and b.) you may be able to shine some light on the "polarity situation", or whatever else may have resulted in the light output being rather dim, and can let me know.
But, I'm getting ahead of myself... Let's continue:

1.) Identifying the polarity of the LEDs was unsuccessful - for the most part - as the new suckers (=LED) didn't feel like lighting up. Never.
At first, I though they might have been damaged in transit, or I was sold 100 defect units .. Until I put two 1.5 AAA together, soldered a wire on each (+) and (-) side, and then used the free ends as leads, sending electricity to the LEDs by touching their connectors. Much to my surprise, every LEDs I touched/checked lit up!
It was a different story with the amber OEM LEDs (the existing ones that are soldered on a strip of flexible circuit board inside the cockpit unit/cluster): I got a readout on those every time, too. However, I did not know how to interpret the needle movement; meaning, which side was positive, and which negative? If I have the black (-) lead attached to one side of the LED, and then touch the other side with the red (+) lead, and the needle moves, what does this tell me about the polarity? Does it mean that the LED connector that I touch with the red (+) lead is positive... or is it the opposite, and it's actually the negative end...? I still don't know for sure.

To me it would make all the sense in the world that the side I touched last/with the red (+) lead (which made the multi-meter needle move upon touching it) actually is of opposite charge; meaning, it's the negative side of the LED. Why? Because the circuit is closed now, electricity is flowing, which is registered by the multi-meter. Since I thought it makes a lot of sense, I made a red dot (with a Sharpie) on the -what I though to be the- positive side of the LED.
But, since I couldn't measure the polarity of the new LEDs with the multi-meter, I used the 3V battery pack to make the LEDs light up and then marked the side that I though was positive. So far, so good.
When I was done soldering, I put the 3V AAA power to the LEDs and they lit up... at least, 50% did. When I then checked another one of the LEDs that I had just soldered on, it lit up either one other LED, or all of them.... Pretty confusing

2.) Even though there is white light coming from behind the right (RPM) gauge, it does not seem bright enough - nowhere near what it should be (at least, not in daylight).
This leads me to believe that 50% of the new LEDs must have been soldered onto the circuit board with the polarity reversed. At least, that's my explanation... I am just surprised, though, that they are working at all: since I may have managed to connect 50% of the LEDs incorrectly, shouldn't they all be off then???

3.) I managed to mix up my 2,500mcd LEDs with the 2,000mcd LEDs, which I also bought (just in case 2,500mcd is too bright)...
After testing the light output with "the naked eye", to differentiate between 2000 and 2500mcd, I thought that I had identified the 2,500mcd batch and used those LEDs for the mod. I might have been wrong, though, which may yet be another explanation for the LED lights now being as bright as expected... at least, in daylight.


Things I should have done better right from the get-go:
1.) I should have used the finest tip for my soldering iron... but I failed to realize that sooner.
Hence, it got pretty messy when trying to get the LEDs off/on the flex circuit board. I'm sure my next stab at this will be more precise, as I have replaced the tip now;
2.) Would have been extremely beneficial to have magnification... either by means of magnifying goggles, or by using that "3rd hand" stand with clamp & magnifying glass that I have somewhere in my home office, but couldn't find since I just recently moved to a new place


One slight correction concerning the otherwise awesome DIY by PinguHK and Ricky:
The screwdriver size needed for step 09 (as per PinguHKs very first post) is a T8, not a T9.

Lastly:
This mod is not as difficult as it seems... IF:
- you are patient, and
- use good tools (in general), and
- use a half-way decent/capable soldering iron and multi-meter.

As a matter of fact, I used exactly the same tools (=fork, plastic card & sliding caliper etc.) as shown by Pinguhk, and I didn't have a problems taking the cluster apart. (Getting it back together was a different story... Buy, hey - I succeeded after all :-)


I'll do some more adjustments/corrections to my first cluster mod next weekend. Among others, I'll change the speedometer gauge LEDs to white then, too - using a new/better multimeter this time....


Let me know if you'd like to add anything to my findings, or have any kind of helpful suggestions.
(P.S.: Be sure to keep 'sarcasm' or 'funny comments' to yourselves, though... - Thanks!)

Cheers,
Armin

stel_i79

a lot to read )

nice explain....

i wish u good luck...
i had done my cluster at john...in ny...so nice..

ZGERMAN

Thanks, man.... appreciate it!
Yep, my writeup got a bit longer, I guess. Must be the detail-focused German in me....

OK, time for a picture now:



Doesn't look all that bad, does it?
And yes; I've cut corners by purchasing a set of red OEM M5 needles off eBay... he he! One thing less to mess with

The brightness of the RPM gauge is OK, but not as bright as it should be. Definitely running on 50% of the LEDs only, I'd say. Anyway, I like it very much already!! Will be much brighter next weekend, that's for sure!

Good thing the next (modding)weekend is here in just 5.5 more work days...

stel_i79

this is...mine...from profile...
..when u look from straight..is so bright...

ZGERMAN

Very NICE, bud... looks awesome!!
That's how I want mine to look like, too, when my cluster mod is completed this coming weekend.... I want it BLINDINGLY BRIGHT !

balbs

Do you have the link to the OEM M5 needles from eBay? Great job man!