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Discussion Starter #1
My wifes 2003 ML270 has an issue that I can only think is something related to the heater, a couple of days ago we noticed a smell of burning 10 minutes into our journey, I messed with the heater controls, turned the heater off and back on and all okay for the remaining 2 hour journey, she's used to for the school runs okay then today she got the same electrical smell and some black smoke out of the heater vents.
I've taken the car for a spin twice, messing with the heater and nothing, nothing at all.
Can anyone help, wife is a bit worried about being fried alive with the kiddies!!!!:confused:
 

W163 Crash Test Driver
2008 ML350 (Me!), 2010 GLK350 (Wife), 2003 ML-350 (Deceased)
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My wifes 2003 ML270 has an issue that I can only think is something related to the heater, a couple of days ago we noticed a smell of burning 10 minutes into our journey, I messed with the heater controls, turned the heater off and back on and all okay for the remaining 2 hour journey, she's used to for the school runs okay then today she got the same electrical smell and some black smoke out of the heater vents.
I've taken the car for a spin twice, messing with the heater and nothing, nothing at all.
Can anyone help, wife is a bit worried about being fried alive with the kiddies!!!!:confused:
Perhaps your blower motor is dieing? I can't think of anything else electrical that could send actual smoke out of the vents. The heater itself works off the engine coolant, it's basically a small radiator and isn't electrical in nature.
 

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If this if first time you have used heater this season dust on electric heater booster is burning off. It will last few minutes then disappear. If it persists have it checked. US models don't have that feature so there is no diagnostic info about it. Look for the fuse and pull it out in meantime.
 

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1990 190E 2.6,.... 1998 ML320, 2005 ML500SE
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I have had this happen twice. The first time was several years age in my Ford Bronco. The blower motor speed reducing resistors are mounted in the heater air duct and set some leaves on fire that had been sucked in to the heater duct. Luckily the fire went out as soon as I shut the vehicle off. It took me a full day of tearing the heater duct work apart before I found out what had happened. I vacuumed everything out and all was well.
It happened again in my Mercedes 190E just last week. I posted the problem on the BenzWorld 190E forum. Again dust and other trash had gotten into the heater motor speed reducing resistors and was smoldering. I vacuumed all the debris out and the burning smell went away. The lower the blower motor speed the hotter the resistor pack gets so the slower the speed the more the burning smell will be. The resistor pack in most all vehicles consists of coils of wire not common electronic circuit resistors.
The resistor pack in the ML is located in the heater duct just before the cabin air filter.
I suggest you remove your cabin air filter and vacuum everything out. While there you may want to remove the resistor pack and vacuum that area out also. I bet you will find a lot of junk in there.
Mike
 

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Discussion Starter #5
I have the answer, thank you for all your help!!
It is the heated seat burning a hole through the drivers seat, the reason why we all thought it was coming through the heater was that the air circulation was drawing the air from the burning seat toward the open dash vent which then blew the smoke straight at your face whilst driving!!!
I've now looked on this site for burning seats which it appears to be very common fault!!!
I doubt MBUK will honour this as a good will gesture to a 2003 out of warranty ML????
 

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1990 190E 2.6,.... 1998 ML320, 2005 ML500SE
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That's a shame. I love my heated seats and have had to replace the drives bottom seat heater in both my 98ML320 and 05ML500. My 05ML was fixed under extended warranty just last month. Obviously a poor design for both types of seat heaters.
Now that the cold weather is coming we are probably going to see a lot more posts regarding defective heated seats. There are several recent posts already.
Mike
 

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Discussion Starter #7
I've managed to buy a saphron java seat base from ebay, right part number, MB new and unused for 25% of retail price :D

Now need to find a thread on how to change the seat base?
 
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