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murreywalker · 05-25-2011, 08:49 AM

I have a 2010 MB GL and it has LED lights.

The 2011 FC 23FB also has LEDs.

Problem: It appears there is a resistance issue between LED sets that cause (when the tow vehicle has its headlights on) the trailer running lights to blink on and off quickly.

etrailer.com has an adaptor 7 pin cable that MB says takes care of the issue.

Etrailer will not have any in supply until July.

Does anyone know of an alternative solution to this issue?

TIA

Wayne&Sam · 05-25-2011, 09:13 AM

I've heard of some folks wiring in incandescent bulbs just to provide the resistance, but I also think you can get the adapter from Andrew T.

Dan@LED4RV · 05-25-2011, 09:48 AM

In a earlier post I read where someone found the running and stop lights wires under the couch, and put a incandescent bulb in-line there, to get the resistance to allow the LED lights to work. I'm not sure where your wires are but having a light inside your unit and not touching anything to where the heat from the light would not cause any problems should be fine. To get you on your way.

mojo · 05-25-2011, 10:11 AM

You can get the adapter from VW dealers but it will cost more than at Etrailer.

murreywalker · 05-25-2011, 10:21 AM

Quote:

Originally Posted by mojo

You can get the adapter from VW dealers but it will cost more than at Etrailer.

Are you sure VW has the adapter? Etrailer has them on backorder and won't have them until July.

murreywalker · 05-25-2011, 10:37 AM

Quote:

Originally Posted by Wayne&Sam

I've heard of some folks wiring in incandescent bulbs just to provide the resistance, but I also think you can get the adapter from Andrew T.

I talked with them and they suggested the incandescent method.

The harness is located under the bed and splicing in sockets to hold bayonet style bulbs in three wires would be a solution to the issue.

What I don't understand is, why didn't Airstream address this issue when they knew it (I talked with them earlier this morning, and they acknowledged it was an issue)?

xrvr · 05-25-2011, 11:27 AM

I believe this is a tow vehicle problem not an AS problem. AS can't be expected to solve every issue that may come up with all the diferent types of tv. Same as hitches, if it will not work on an AS, then it is not AS problem, it is the hitch mfg problem. Go to your MB dealer and ask them why their car will not work with the AS. I bet they will say something like--we can't make our car compatible with every trailer mfg. Same as AS , they can't make their trailers work with every tv made. jim

murreywalker · 05-25-2011, 11:32 AM

Quote:

Originally Posted by zigzagguzzi

I believe this is a tow vehicle problem not an AS problem. AS can't be expected to solve every issue that may come up with all the diferent types of tv. Same as hitches, if it will not work on an AS, then it is not AS problem, it is the hitch mfg problem. Go to your MB dealer and ask them why their car will not work with the AS. I bet they will say something like--we can't make our car compatible with every trailer mfg. Same as AS , they can't make their trailers work with every tv made. jim

Seems to me to be a chicken or egg issue, jim. It is, indeed, an engineering challenge.

However if I knew there was an issue in MY manufacturing process that impacted a growing body of users, I probably would spend some time and effort in providing a solution to my future customers.

JMHO, though.

xrvr · 05-25-2011, 11:40 AM

Okay, so why isn't MB doing that? jim

murreywalker · 05-25-2011, 12:19 PM

Quote:

Originally Posted by zigzagguzzi

Okay, so why isn't MB doing that? jim

I don't know that they aren't.

worldinchaos · 05-25-2011, 01:26 PM

I'm not familiar with this issue, but is it related to the power to the LED being too high with not enough resistance? Alternatively if it is because of the aspect of using LEDs for both, couldn't you just wire in a relay with a separate lead from the battery in order to have direct power to the lights, and then put a load resistor on it? You can pick those up at Fry's or Radioshack.

Wayne&Sam · 05-25-2011, 02:40 PM

Quote:

Originally Posted by zigzagguzzi

Okay, so why isn't MB doing that? jim

I think you can count those of us who tow with a Mercedes on one hand.

**DKB_SATX** · 05-25-2011, 02:57 PM

Quote:

Originally Posted by worldinchaos

I'm not familiar with this issue, but is it related to the power to the LED being too high with not enough resistance? Alternatively if it is because of the aspect of using LEDs for both, couldn't you just wire in a relay with a separate lead from the battery in order to have direct power to the lights, and then put a load resistor on it? You can pick those up at Fry's or Radioshack.

I'm guessing that the "adapters" mentioned that are out of stock are nothing more than an appropriately-sized resistor.

It sounds like the same behavior that modern cars exhibit when a lamp burns out, but applied to the running lamps instead of the turn lamps. I'd assumed it was an intentional design for turn signals, so that you're alerted that a lamp is out. I wonder if it's an inadvertent "feature" that's triggered for the running lights as well, since many modern high-tech cars don't have mechanical flashers anymore, it's done by one of the onboard computer modules.

murreywalker · 05-25-2011, 03:32 PM

Quote:

Originally Posted by Wayne&Sam

I think you can count those of us who tow with a Mercedes on one hand.

It not only applies to MB. Audi, VW and Porsche Cayenne seem to be having the same issue.

Lot's of good feedback from many of you, but so far I'm of the opinion that installing incandescent sockets with bulbs at the right location in the trailer, seems to be the best approach.

Of course, as LED technology becomes more prolific, the solutions will rush to the marketplace.

murreywalker · 05-25-2011, 03:36 PM

Quote:

Originally Posted by DKB_SATX

I'm guessing that the "adapters" mentioned that are out of stock are nothing more than an appropriately-sized resistor.

It sounds like the same behavior that modern cars exhibit when a lamp burns out, but applied to the running lamps instead of the turn lamps. I'd assumed it was an intentional design for turn signals, so that you're alerted that a lamp is out. I wonder if it's an inadvertent "feature" that's triggered for the running lights as well, since many modern high-tech cars don't have mechanical flashers anymore, it's done by one of the onboard computer modules.

I've been told by MB Tech that the one of the computer modules is getting the wrong reading. MB is slow in adapting technology, but when they do, they do it well, but at this juncture, I really can't point the finger at MB or Airstream because of my lack of electrical understanding.

But, both entities are well aware of the issue.

mojo · 05-25-2011, 04:04 PM

Murrey, I got my adapter from VW because back then that was the only source. It works well and gives me the added length needed for a Hensley hitch. This is a problem with most European cars, VW, MB, Porsche, Land Rover and Audi. You'll have to call and order one from whatever source you can find. Or as others said, wire in a bulb or resistor if you're handy with electronics. Your lights should work in the meantime, but they may start flashing even when parked with the ignition off.

klattu · 05-25-2011, 04:39 PM

Change your flasher, get one that blinks based on time, not heat.
Most all auto parts stores will have them... about $10
If you change to LEDs thats the way to go.

Wayne&Sam · 05-25-2011, 06:07 PM

Quote:

Originally Posted by murreywalker

It not only applies to MB. Audi, VW and Porsche Cayenne seem to be having the same issue.

Lot's of good feedback from many of you, but so far I'm of the opinion that installing incandescent sockets with bulbs at the right location in the trailer, seems to be the best approach.

Of course, as LED technology becomes more prolific, the solutions will rush to the marketplace.

True, but again, these vehicles aren't marketed for towing, so I think that's why they are all slow to react.

I'm guessing the big tow vehicles - pick ups, Suburbans etc.- don't have leds lights yet.

Davern1 · 05-25-2011, 07:37 PM

I have that issue with my Cayenne and use that adapter from Etrailer sometimes for larger trips. As I understand it, the computer module in BMW, Mercedes, Porsche, and some other euro cars sends a low level pulse throughout the brake system that checks for burned out trailer or brake lights. If I don't have the harness plugged in I get a check trailer light error message even though they work fine and the flashing that you see isn't readily apparent in the day light but is at night. It's related to the same issue that many of these suvs have trouble with certain brake controllers. By putting the incandesant bulb inline it increases the load on the system and the SUVs computer thinks all the bulbs are fine. This really isn't an Airstream issue in my opionion. The engineers of these cars set the system up to check the trailer lights. There are so many variations of trailers that this is hard to do. Id rather my car not check the lights and I would continue to do the pre trip walkaround.