I have a small motorcycle trailer that had a burned out tail light. It's the kind that's sealed and you have to replace the whole light. The trailer plugs into my 08 MB ML and the car monitors the lights, changes the tranny shifting values among other things. So I replaced the lights with LED lights of the same size. When I plugged them in all lights on the trailer started blinking like flashers. So the vehicle doesn't like the new lights. Do I need some kind of adapter or something? Is it the LED lights?
Trailer lights question.
- Thread starter loneryder
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Well the first thing to check is a proper ground. You need to run a ground wire from the plug (that plugs into the car) to each light. Using the trailer frame is always suspect.
99% of the time its a ground issue.
99% of the time its a ground issue.
I would try switching the polarity on one light, and try it ,then the other.
And I agree with Donald, grounds are frequently the problem.
And I agree with Donald, grounds are frequently the problem.
If still problems get a source of 12V and with clip leads, provide 12V directly to the trailer plug. Moving the positive to each of the 3 male connectors and see if you have lights as expected.
If I'm reading the OP correctly, the old lamp had a filament-based bulb, while the new ones are LED. Is it possible the resistance value of the new lamp is lower, and the ML is seeing that as a problem? I wonder if checking some MB ML specific forums might help. If others have replaced lamps on the vehicle with LED and had similar odd behaviour, those threads might also have the solution. I've seen posters on other forums talk about having to add a resistor to correct the lower resistance value of an LED retrofit.
Thanks guys. I've done some further investigation and it seems MB and other German cars don't like LED trailer lights. I think I need some resisters and just need to figure out the best way to install them. The MB tow pkg system is set up for incandescent lights.
One of my parents Escapes had a recall for exactly this. If you plugged in a trailer with all LED lights to a factory-towing package equipped Escape it would freak out the CANBUS.
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