PDA

View Full Version : Att: shogun and anyone else interested in LKM



Incantation
10-11-2005, 04:21 PM
so dude.. i went to my mechanic and he had a spare lkm sitting around so i plugged it in .. and yea it turns out to be the lkm that is causing my light to not function..

he wanted 220 CAN for it.. what a joke. a new one is something close to that..

anyway.. so i thought i had re-soldered it all properly but i guess what i will have to do is strip all the re-soldered stuff off ( i had done the intermittent lkm fix last year) and just re-do it all.. hopefully that will work


one question.. is it plausible that using a higher wattage bulb could burn out the lkm?

anyway.. so to anyone who suffers one low-beam not working (as opposed to the common intermittent symptom) it would be worth it to check the lkm out ..

:)

Torque
10-11-2005, 04:27 PM
Higher wattage bulb would likely burn the wiring. I haven't heard of anyone that burned out the LKM with a higher wattage bulb, but there's always a chance.

GS535i
10-11-2005, 05:54 PM
In addition to soldering ( or stripping & resoldering) the LKMs PC, check for continuity through the closed points position of the mini-relays ( whose PC contacts are ~ 90% of the problem anyway). When I first did one, the fog light relay had a burned contact that required careful cleaning to restore the circuit path.

Incantation
10-11-2005, 07:28 PM
you know what's interesting.. i was looking at the lkm relative to the picture in bmwe34.net:

http://www.bmwe34.net/e34main/maintenance/electrical/Data/LKM.jpg

and i don't have the second relay from the left. i have the far left one and the two on the right side..

?!?

i am pretty stumped.. i did a solid soldering job.. oh well here goes

uscharalph
10-11-2005, 08:27 PM
so dude.. i went to my mechanic and he had a spare lkm sitting around so i plugged it in .. and yea it turns out to be the lkm that is causing my light to not function..

he wanted 220 CAN for it.. what a joke. a new one is something close to that..

anyway.. so i thought i had re-soldered it all properly but i guess what i will have to do is strip all the re-soldered stuff off ( i had done the intermittent lkm fix last year) and just re-do it all.. hopefully that will work


one question.. is it plausible that using a higher wattage bulb could burn out the lkm?

anyway.. so to anyone who suffers one low-beam not working (as opposed to the common intermittent symptom) it would be worth it to check the lkm out ..

:)
The LKM soldering job plus a new bulb solved my problem.

liquidtiger720
10-11-2005, 08:37 PM
OT: but is there anywhere i can read up on soldering stuff correctly?

Gayle
10-11-2005, 08:41 PM
OT: but is there anywhere i can read up on soldering stuff correctly?


Second that question.

Bill R.
10-11-2005, 08:57 PM
well documented...alot of the guys that were running high wattage bulbs were torching the lkm's





so dude.. i went to my mechanic and he had a spare lkm sitting around so i plugged it in .. and yea it turns out to be the lkm that is causing my light to not function..

he wanted 220 CAN for it.. what a joke. a new one is something close to that..

anyway.. so i thought i had re-soldered it all properly but i guess what i will have to do is strip all the re-soldered stuff off ( i had done the intermittent lkm fix last year) and just re-do it all.. hopefully that will work


one question.. is it plausible that using a higher wattage bulb could burn out the lkm?

anyway.. so to anyone who suffers one low-beam not working (as opposed to the common intermittent symptom) it would be worth it to check the lkm out ..

:)

Bill R.
10-11-2005, 08:58 PM
sweatshop jobs in electronic assembly.



OT: but is there anywhere i can read up on soldering stuff correctly?

ryan roopnarine
10-11-2005, 09:12 PM
well documented...alot of the guys that were running high wattage bulbs were torching the lkm's


bill, when you say "high wattage", do you mean 9005 (65w) bulbs or significantly higher? i've never heard of such a problem, but if it is, ill just substitute xtravisions in for my 55 watt lights.

SRR2
10-11-2005, 09:23 PM
I agree that a course at a community college might fill the bill. You'll also need a certain minimum quality of equipment and supplies. I'd recommend a temperature-controlled iron with a GROUNDED tip as a starter. You'll need solder, solder wick, small hand tools (pliers, cutters, etc.), good lighting, antistatic wrist strap, preferably some sort of static-reduced workstation surface. Some other useful items would include solvent and brushes to remove conformal coating, low-acid adhesives to hold larger components down on the board (note: ordinary RTV - silicone rubber - is NOT acceptable for electronics work! It releases acetic acid as it cures and will damage components and circuit boards), an assortment of wire, and wire strippers... and so on. It's not too different, I suppose, than setting yourself up to do mechanical work under the hood. There's a certain minimum level of equipment and tools that are required for entry.

I just want to reinforce one point: working on technology like the cluster isn't rocket surgery, but it does require attention to detail and a degree of care in protecting the board from static discharge and soldering-iron transients. There are a LOT of crappy soldering irons that will destroy static-sensitive circuits the first time they switch off. If you're serious about working on electronics, for crying out loud, get a quality soldering iron because you WILL destroy your cluster with some garbage irons. It doesn't have to be a $400 digital Weller, but it should be temperature controlled and have interchangeable tips. If anyone's interested, I can make some recommendations. You can also browse DigiKey's online catalog to see what kinds of equipment are available.

shogun
10-11-2005, 09:31 PM
I once had 12V H1 100W bulbs in the headlights for only a few days. Then the plastic reflectors had bubbles inside and the thin wires inside the cap behind the headlights had no more islolation and one was completely burnt.
But it did not damage my LKM.
Aren't the fuses in between?
As for soldering electronics, there is a nice instruction on my bewbsite, but in German. Therefore take this one
http://www.epemag.wimborne.co.uk/solderfaq.htm

The LKM's comes in various versions. Besides LKM-B and LKM-L there are country specific ones. So I have the LKM-L-J = Japan version.
That does have one relay less than the ECE version, as we do not have rear fog lights. Even there are some pins not connected on my one. Just yesterday I got an LKM-L-J back from my friend in Germany, which wanted to see it to compare the differences. He is an electronic expert and has the details.

BTW: when you have funny messages like "ESD regelt" or similar ones, resolder the CCM.
ESD regelt" is a message that should not appear at all. There was never an ESD (= elektronisches Sperrdifferenzial = electronic limited slip differential) in the E34, same thing with the E32. that's the reason why this message isn't translated by the Check Control into English.

try to resolder the R60, R61 and R62 resistor in your Check Control Module or replace it.

Bill R.
10-11-2005, 11:41 PM
I haven't seen it with 65watt.



bill, when you say "high wattage", do you mean 9005 (65w) bulbs or significantly higher? i've never heard of such a problem, but if it is, ill just substitute xtravisions in for my 55 watt lights.

Incantation
10-12-2005, 01:57 AM
nice.. thanks man

Incantation
10-12-2005, 01:58 AM
:( ... and by torching i am assuming irreversible damage.. :\