Water /moisture in headlight housing
Is it a big issue if this happens after a soaking rain?
The service tech said this happens every now and then but its been 4 days and still moist with condensation.
MB Service will Drill an opening in the light housing and install a moisture removal desiccants pack. I did not have this done, but the moisture is bad enough at times that the moisture actually runs down the inside of the light. At some point this must mess up the optics / water marks inside the housing....
Last edited by adjax; Mar 28, 2017 at 03:11 AM.
Mine is no longer holding water after that first week. I wash it regularly in a car wash (that I trust) and it has never returned. Thanks for the reply.
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I took it to the dealer and they fixed it again under warranty. However, this was in their notes this time, so I am not sure how good their previous fix was?:
" 8818 RIGHT HEADLAMP MODULE SHORTED OUT, AND DESICANT PACK FULL AND
SEEPING FLUID W CONNECTED BATTERY CHARGER, CONNECTED SDS, AND PERFORMED
SHORT TEST. FOUND CURRENT FAULT CODE: B17ED11 The output for the low
beams has a malfunction. There is a short circuit to ground. IN E2n9 -
Right headlamp (SG-SW-R). PROCESSED FAULT CODE, R&R FRONT BUMPER, R&R
RIGHT HEADLAMP UNIT AND INSPECTED. REMOVED CONTROL UNIT AND FOUND THAT
LI82.10-P-062051 HAD BEEN PREVIOUSLY PERFORMED. FOUND THAT DESICANT
PACK WAS FULL AND HAD LEAKED MOISTURE OUT ONTO CONTROL UNIT SHORTING IT
OUT. R&R LEFT HEADLAMP AND INSPECTED AND FOUND THAT DESICANT PACK ALSO
FULL. REPLACED DESICANT PACKS IN BOTH HEADLAMP UNITS. REPLACED PASS.
HEAD LAMP UNIT, AND CONTROL UNIT. PERFORMED CODING OF CONTROL UNIT.
CLEARED FAULT CODES, AND VERIFIED REPAIRS.
*******************************************"
I took it to the dealer and they fixed it again under warranty. However, this was in their notes this time, so I am not sure how good their previous fix was?:
" 8818 RIGHT HEADLAMP MODULE SHORTED OUT, AND DESICANT PACK FULL AND
SEEPING FLUID W CONNECTED BATTERY CHARGER, CONNECTED SDS, AND PERFORMED
SHORT TEST. FOUND CURRENT FAULT CODE: B17ED11 The output for the low
beams has a malfunction. There is a short circuit to ground. IN E2n9 -
Right headlamp (SG-SW-R). PROCESSED FAULT CODE, R&R FRONT BUMPER, R&R
RIGHT HEADLAMP UNIT AND INSPECTED. REMOVED CONTROL UNIT AND FOUND THAT
LI82.10-P-062051 HAD BEEN PREVIOUSLY PERFORMED. FOUND THAT DESICANT
PACK WAS FULL AND HAD LEAKED MOISTURE OUT ONTO CONTROL UNIT SHORTING IT
OUT. R&R LEFT HEADLAMP AND INSPECTED AND FOUND THAT DESICANT PACK ALSO
FULL. REPLACED DESICANT PACKS IN BOTH HEADLAMP UNITS. REPLACED PASS.
HEAD LAMP UNIT, AND CONTROL UNIT. PERFORMED CODING OF CONTROL UNIT.
CLEARED FAULT CODES, AND VERIFIED REPAIRS.
*******************************************"
A C/S: ACTIVE HEADLAMPS INOP / CHECK AND ADVISE
CAUSE: F
824730 REMOVE/INSTALL 2 FRONT LAMP UNITS
625 W08 (N/C)
1 222-906-22-04 HEADLAMP UNIT (N/C)
1 222-870-07-89 VOLTAGE CONVERTER (N/C)
1 000-826-13-00 PROTECTIVE COWL (N/C)
1 000-826-12-00 PROTECTIVE COWL (N/C)
2 000-826-16-00 DEHUMIDIFIER PACKETS (N/C)
611069 REMOVE/INSTALL LOWER ENGINE COMPARTMENT
PANELING COMPLETE
625 W08 (N/C)
540650 ON-BOARD POWER SUPPLY VOLTAGE MAINTAIN
(WHEN CHECKING/ TESTING AND TROUBLESHOOTING)
625 W08 (N/C)
541011 PERFORM QUICK TEST
625 W08 (N/C)
020001 STRAIGHT TIME, FOR USE WITH PUBLISHED
DOCUMENTS ONLY
625 W08 (N/C)
8818 RIGHT HEADLAMP MODULE SHORTED OUT, AND DESICANT PACK FULL AND
SEEPING FLUID W CONNECTED BATTERY CHARGER, CONNECTED SDS, AND PERFORMED
SHORT TEST. FOUND CURRENT FAULT CODE: B17ED11 The output for the low
beams has a malfunction. There is a short circuit to ground. IN E2n9 -
Right headlamp (SG-SW-R). PROCESSED FAULT CODE, R&R FRONT BUMPER, R&R
RIGHT HEADLAMP UNIT AND INSPECTED. REMOVED CONTROL UNIT AND FOUND THAT
LI82.10-P-062051 HAD BEEN PREVIOUSLY PERFORMED. FOUND THAT DESICANT
PACK WAS FULL AND HAD LEAKED MOISTURE OUT ONTO CONTROL UNIT SHORTING IT
OUT. R&R LEFT HEADLAMP AND INSPECTED AND FOUND THAT DESICANT PACK ALSO
FULL. REPLACED DESICANT PACKS IN BOTH HEADLAMP UNITS. REPLACED PASS.
HEAD LAMP UNIT, AND CONTROL UNIT. PERFORMED CODING OF CONTROL UNIT.
CLEARED FAULT CODES, AND VERIFIED REPAIRS.
************************************************** **
A C/S: ACTIVE HEADLAMPS INOP / CHECK AND ADVISE
CAUSE: F
824730 REMOVE/INSTALL 2 FRONT LAMP UNITS
625 W08 (N/C)
1 222-906-22-04 HEADLAMP UNIT (N/C)
1 222-870-07-89 VOLTAGE CONVERTER (N/C)
1 000-826-13-00 PROTECTIVE COWL (N/C)
1 000-826-12-00 PROTECTIVE COWL (N/C)
2 000-826-16-00 DEHUMIDIFIER PACKETS (N/C)
611069 REMOVE/INSTALL LOWER ENGINE COMPARTMENT
PANELING COMPLETE
625 W08 (N/C)
540650 ON-BOARD POWER SUPPLY VOLTAGE MAINTAIN
(WHEN CHECKING/ TESTING AND TROUBLESHOOTING)
625 W08 (N/C)
541011 PERFORM QUICK TEST
625 W08 (N/C)
020001 STRAIGHT TIME, FOR USE WITH PUBLISHED
DOCUMENTS ONLY
625 W08 (N/C)
8818 RIGHT HEADLAMP MODULE SHORTED OUT, AND DESICANT PACK FULL AND
SEEPING FLUID W CONNECTED BATTERY CHARGER, CONNECTED SDS, AND PERFORMED
SHORT TEST. FOUND CURRENT FAULT CODE: B17ED11 The output for the low
beams has a malfunction. There is a short circuit to ground. IN E2n9 -
Right headlamp (SG-SW-R). PROCESSED FAULT CODE, R&R FRONT BUMPER, R&R
RIGHT HEADLAMP UNIT AND INSPECTED. REMOVED CONTROL UNIT AND FOUND THAT
LI82.10-P-062051 HAD BEEN PREVIOUSLY PERFORMED. FOUND THAT DESICANT
PACK WAS FULL AND HAD LEAKED MOISTURE OUT ONTO CONTROL UNIT SHORTING IT
OUT. R&R LEFT HEADLAMP AND INSPECTED AND FOUND THAT DESICANT PACK ALSO
FULL. REPLACED DESICANT PACKS IN BOTH HEADLAMP UNITS. REPLACED PASS.
HEAD LAMP UNIT, AND CONTROL UNIT. PERFORMED CODING OF CONTROL UNIT.
CLEARED FAULT CODES, AND VERIFIED REPAIRS.
************************************************** **
Housing alone is over a grand.... Ouch..
Housing alone is over a grand.... Ouch..
The headlight in both my '16 &'17 coupes fog up. It usually dissipates in a day or so even in humid S FL.
Last edited by RJC; Jun 16, 2017 at 02:07 AM.
They also replaced the 4 Center Caps, starting to Peal at the edges. I strongly suggest anyone still under B2B and plan on keeping the vehicle, you go over the car with a Fine Tooth Comb. ALL trim items are covered. After B2B, CPO will NOT cover trim items.... Sorry for the OCD kicking in again...
"Had the Star Emblem on the steering wheel start to flake off the Chrome coating, Covered under B2B, $2,300- for part. They could not just replace the emblem, its part of the Air Bag.
They also replaced the 4 Center Caps, starting to Peal at the edges. I strongly suggest anyone still under B2B and plan on keeping the vehicle, you go over the car with a Fine Tooth Comb. ALL trim items are covered. After B2B, CPO will NOT cover trim items.... Sorry for the OCD kicking in again...
"
"Had the Star Emblem on the steering wheel start to flake off the Chrome coating, Covered under B2B, $2,300- for part. They could not just replace the emblem, its part of the Air Bag.
They also replaced the 4 Center Caps, starting to Peal at the edges. I strongly suggest anyone still under B2B and plan on keeping the vehicle, you go over the car with a Fine Tooth Comb. ALL trim items are covered. After B2B, CPO will NOT cover trim items.... Sorry for the OCD kicking in again...
"This reminds me that I am again having moisture condensation problems in my headlights (this after they've already placed in the desicant packs and then when that failed, replaced the whole headlamp assembly.








