reverse bulbs led
12-04-2017, 10:12 PM
#1
Senior Member
Thread Starter
reverse bulbs led
Hey guys, quick question. I found out the hard way buy changing to a led bulb for my license plate had to have a built in resister. My question is, this the case with all benz bulbs? I'm mainly asking for the backup bulbs. I wanted to go to a 5000k led backup bulb, but didn't know if it needs a resister.... Anybody know???
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kbanks45 (12-05-2017)
12-05-2017, 11:52 PM
#3
Senior Member
Thread Starter
12-06-2017, 01:33 AM
#4
SPONSOR/MBworld Guru
09-11-2020, 03:29 PM
#5
Senior Member
Unfortunately, MBZ, in its efforts to update its electrical and electronic components has managed to 'fumble the ball' and make a big mess. Different models in different years have incompatible electronics, lights and misc light bulbs everywhere. Starting with 'stone tablets era' the stuff was 6VDC , later 12VDC. The fuses were weird non standard ceramic rods with some kind of easily corroded fuse metal inserted between two brass tangs (circa late horse and buggy) They they 'completely redesigned' everything in the 80's using 1950 technology and straight 12VDC, retaining the horrible fuses. (How they EVER got approval to sell them in the USA blows my mind)
Then they once again redesigned all the electrical stuff and converted SOME things to standard automotive fuses and some transistorized electric components in the late 80's Then in 1990-91 they 'modernized most of the electrical wiring with 'environment friendly plastic insulation -'upgrading' from WW-II friction tape and fabric wraps. The new environmental friendly wiring insulation was 'biodegradable' supposedly to make it easier to recover and recycle the copper in the wires. The stuff begain failing in 2-4 years requiring complete replacement of all the wiring harnesses--which unless one could get MBZ warranty replacement could cost more than $20,000 for S-Class vehicles for damaged 'computers' and more than100 wkhrs. Many thousand of vehicles from 1990 thru 1996 models were not economically worth the repairs and met early deaths (and more than a few accidents.) How Mercedes avoided a mandatory Safety Recall is a class example of how Corporate Clout got away with fraud on the U.S. customers. Then MBZ began once again 'modernizing' starting to 'go digital', but again they blew it. The 'integrated electronics' did not work together very well with many many non fixable problems. Light bulbs were not industry standard with a dozen or more DIFFERENT non-standard non-industry spec bulbs in a single car, and using a non-MBZ spec bulb would often fry things, fail, and cause weird error and warning messages to appear in the instrument cluster.. They used several different, non-compatible 'network' systems, each requiring completely different components. When owners tried to switch to low current 12VDC LED bulbs, error messages of' "bulb failure' because the LED bulbs used much less current, and MBZ's non standard bulb failure detection system would call it a failed bulb. The only 'fix' was/is to install low-resistance high wattage resistors in parallel with the LED bulbs to 'use more current' so the flaky bulb failure detection would stay 'happy. IF the owner did not remote mount on heat sinks the high heat generating resistors for all the bulbs in a tail-light assembly would heat up the plastic assembly past the melting point, ruining it and causing fires.
YOU HAVE to calculate how many Ohms of high current capacity resistor you need connected in parallel with each LED to closely match the wattage of each old bulb. The fewer the Ohms the more current (watts.) Have fun
Then they once again redesigned all the electrical stuff and converted SOME things to standard automotive fuses and some transistorized electric components in the late 80's Then in 1990-91 they 'modernized most of the electrical wiring with 'environment friendly plastic insulation -'upgrading' from WW-II friction tape and fabric wraps. The new environmental friendly wiring insulation was 'biodegradable' supposedly to make it easier to recover and recycle the copper in the wires. The stuff begain failing in 2-4 years requiring complete replacement of all the wiring harnesses--which unless one could get MBZ warranty replacement could cost more than $20,000 for S-Class vehicles for damaged 'computers' and more than100 wkhrs. Many thousand of vehicles from 1990 thru 1996 models were not economically worth the repairs and met early deaths (and more than a few accidents.) How Mercedes avoided a mandatory Safety Recall is a class example of how Corporate Clout got away with fraud on the U.S. customers. Then MBZ began once again 'modernizing' starting to 'go digital', but again they blew it. The 'integrated electronics' did not work together very well with many many non fixable problems. Light bulbs were not industry standard with a dozen or more DIFFERENT non-standard non-industry spec bulbs in a single car, and using a non-MBZ spec bulb would often fry things, fail, and cause weird error and warning messages to appear in the instrument cluster.. They used several different, non-compatible 'network' systems, each requiring completely different components. When owners tried to switch to low current 12VDC LED bulbs, error messages of' "bulb failure' because the LED bulbs used much less current, and MBZ's non standard bulb failure detection system would call it a failed bulb. The only 'fix' was/is to install low-resistance high wattage resistors in parallel with the LED bulbs to 'use more current' so the flaky bulb failure detection would stay 'happy. IF the owner did not remote mount on heat sinks the high heat generating resistors for all the bulbs in a tail-light assembly would heat up the plastic assembly past the melting point, ruining it and causing fires.
YOU HAVE to calculate how many Ohms of high current capacity resistor you need connected in parallel with each LED to closely match the wattage of each old bulb. The fewer the Ohms the more current (watts.) Have fun
